diff --git a/apps/emqx_rule_engine/src/emqx_rule_actions.erl b/apps/emqx_rule_engine/src/emqx_rule_actions.erl
index ea94bff22..1ecf134cb 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_actions.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_actions.erl
@@ -35,23 +35,27 @@
             },
             target_qos => #{
                 order => 2,
-                type => string,
+                type => editable_select,
+                enum => [<<"0">>, <<"1">>, <<"2">>],
                 required => true,
                 default => <<"0">>,
                 title => #{en => <<"Target QoS">>,
                            zh => <<"目的 QoS"/utf8>>},
                 description => #{en =>
                                     <<"The QoS Level to be uses when republishing the message."
-                                      " Set to -1 to use the original QoS."
-                                      " Support placeholder variables.">>,
+                                      " Support placeholder variables."
+                                      " Set to ${qos} to use the original QoS."
+                                      " Or other variable, value is 0 or 1 or 2">>,
                                  zh =>
-                                    <<"重新发布消息时用的 QoS 级别, 设置为 -1 以使用原消息中的 QoS。"
-                                      "支持占位符变量"/utf8>>}
+                                    <<"重新发布消息时用的 QoS 级别。"
+                                      "支持占位符变量，可以使用 ${qos} 来使用原消息的 QoS，"
+                                      "或其他值为 0 或 1 或 2 的变量。"/utf8>>}
             },
             target_retain => #{
                 order => 3,
-                type => string,
-                required => true,
+                type => editable_select,
+                enum => [<<"true">>, <<"false">>],
+                required => false,
                 default => <<"false">>,
                 title => #{en => <<"Target Retain">>,
                            zh => <<"目标保留消息标识"/utf8>>},
@@ -226,9 +230,9 @@ on_action_republish(Selected, _Envs = #{
                     timestamp = erlang:system_time(millisecond)
                 },
             increase_and_publish(ActId, Message);
-        Error ->
+        Errors ->
             emqx_rule_metrics:inc_actions_error(ActId),
-            _ = log_error(Error),
+            _ = log_error(Errors),
             {badact, bad_qos_retain}
     end.
 
@@ -257,54 +261,53 @@ format_msg([], Data) ->
 format_msg(Tokens, Data) ->
      emqx_rule_utils:proc_tmpl(Tokens, Data).
 
-get_qos(-1, _Data) -> {ok, 0};
-get_qos(0, _Data) ->  {ok, 0};
-get_qos(1, _Data) ->  {ok, 1};
-get_qos(2, _Data) ->  {ok, 2};
-get_qos({path, Path}, Data) ->
-    to_qos(emqx_rule_maps:nested_get({path, Path}, Data, 0)).
-
-to_qos(0) ->        {ok, 0};
-to_qos(1) ->        {ok, 1};
-to_qos(2) ->        {ok, 2};
-to_qos(<<"-1">>) -> {ok, 0};
-to_qos(<<"0">>) ->  {ok, 0};
-to_qos(<<"1">>) ->  {ok, 1};
-to_qos(<<"2">>) ->  {ok, 2};
 to_qos(TargetQoS) ->
-    case parse_value_or_placeholder(TargetQoS) of
-        {path, P} ->
-            {ok, {path, P}};
-        _ ->
-            {error, bad_qos}
+    case get_qos(TargetQoS) of
+        {ok, QoS} ->
+            {ok, QoS};
+        _Error ->
+            case emqx_rule_utils:preproc_tmpl(TargetQoS) of
+                Tmpl = [{var, _}] ->
+                    {ok, Tmpl};
+                _ ->
+                    {error, bad_qos}
+            end
     end.
 
-get_retain(false, _Data) -> {ok, false};
-get_retain(true, _Data) ->  {ok, true};
-get_retain({path, Path}, Data) ->
-    to_retain(emqx_rule_maps:nested_get({path, Path}, Data, true)).
+get_qos(Tmpl, Data) ->
+    get_qos(emqx_rule_utils:replace_simple_var(Tmpl, Data)).
+
+get_qos(<<"-1">>) -> {ok, 0};
+get_qos(<<"0">>) ->  {ok, 0};
+get_qos(<<"1">>) ->  {ok, 1};
+get_qos(<<"2">>) ->  {ok, 2};
+get_qos(0) ->        {ok, 0};
+get_qos(1) ->        {ok, 1};
+get_qos(2) ->        {ok, 2};
+get_qos(_) ->        {error, bad_qos}.
 
-to_retain(true) ->        {ok, true};
-to_retain(false) ->       {ok, false};
-to_retain(<<"true">>) ->  {ok, true};
-to_retain(<<"false">>) -> {ok, false};
-to_retain(<<"1">>) ->     {ok, true};
-to_retain(<<"0">>) ->     {ok, false};
-to_retain(1) ->           {ok, true};
-to_retain(0) ->           {ok, false};
 to_retain(TargetRetain) ->
-    case parse_value_or_placeholder(TargetRetain) of
-        {path, P} ->
-            {ok, {path, P}};
-        _ ->
-            {error, bad_retain}
+    case get_retain(TargetRetain) of
+        {ok, Retain} ->
+            {ok, Retain};
+        _Error ->
+            case emqx_rule_utils:preproc_tmpl(TargetRetain) of
+                Tmpl = [{var, _}] ->
+                    {ok, Tmpl};
+                _ ->
+                    {error, bad_retain}
+            end
     end.
 
-parse_value_or_placeholder(ValueOrPlaceholder) ->
-    case re:run(ValueOrPlaceholder, "^\\$\{.+\}$") of
-        nomatch ->
-            ValueOrPlaceholder;
-        {match, [{0, Length}]} ->
-            Placeholder = binary:part(ValueOrPlaceholder, 2, Length - 3),
-            {path, [{key, Key} || Key <- string:lexemes(Placeholder, ". ")]}
-    end.
+get_retain(Tmpl, Data) ->
+    get_retain(emqx_rule_utils:replace_simple_var(Tmpl, Data)).
+
+get_retain(true) ->        {ok, true};
+get_retain(false) ->       {ok, false};
+get_retain(<<"true">>) ->  {ok, true};
+get_retain(<<"false">>) -> {ok, false};
+get_retain(<<"1">>) ->     {ok, true};
+get_retain(<<"0">>) ->     {ok, false};
+get_retain(1) ->           {ok, true};
+get_retain(0) ->           {ok, false};
+get_retain(_) ->           {error, bad_retain}.
diff --git a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
index 5202b88b3..b92d67e4f 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
+++ b/apps/emqx_rule_engine/src/emqx_rule_engine.appup.src
@@ -2,10 +2,13 @@
 %% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
   [{"4.3.10",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
    {"4.3.9",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_events,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
@@ -15,7 +18,8 @@
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.8",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
      {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
@@ -29,7 +33,8 @@
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]}]},
    {"4.3.7",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
@@ -43,7 +48,8 @@
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
    {"4.3.6",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
@@ -57,7 +63,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.5",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
@@ -71,7 +78,8 @@
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.4",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
@@ -85,7 +93,8 @@
      {load_module,emqx_rule_engine,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.3",
-    [{add_module,emqx_rule_date},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -99,7 +108,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.2",
-    [{add_module,emqx_rule_date},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -114,7 +124,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.1",
-    [{add_module,emqx_rule_date},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -129,7 +140,8 @@
      {load_module,emqx_rule_runtime,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {"4.3.0",
-    [{add_module,emqx_rule_date},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {add_module,emqx_rule_date},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -145,10 +157,13 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
   [{"4.3.10",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]}]},
    {"4.3.9",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_events,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
@@ -158,7 +173,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.8",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
@@ -172,7 +188,8 @@
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.7",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -186,7 +203,8 @@
      {load_module,emqx_rule_registry,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.6",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -200,7 +218,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.5",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -214,7 +233,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.4",
-    [{load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_actions,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
@@ -228,7 +248,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.3",
-    [{load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
@@ -242,7 +263,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.2",
-    [{load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
@@ -257,7 +279,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.1",
-    [{load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_funcs,brutal_purge,soft_purge,[]},
@@ -272,7 +295,8 @@
      {load_module,emqx_rule_engine_api,brutal_purge,soft_purge,[]},
      {delete_module,emqx_rule_date}]},
    {"4.3.0",
-    [{load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_rule_validator,brutal_purge,soft_purge,[]},
+     {load_module,emqx_rule_maps,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_engine_cli,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_sqltester,brutal_purge,soft_purge,[]},
      {load_module,emqx_rule_utils,brutal_purge,soft_purge,[]},
diff --git a/apps/emqx_rule_engine/src/emqx_rule_utils.erl b/apps/emqx_rule_engine/src/emqx_rule_utils.erl
index d287f1ad0..047b9d1af 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_utils.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_utils.erl
@@ -16,6 +16,10 @@
 
 -module(emqx_rule_utils).
 
+-export([ replace_vars_in_str/2
+        , replace_simple_var/2
+        ]).
+
 %% preprocess and process tempalte string with place holders
 -export([ preproc_tmpl/1
         , proc_tmpl/2
@@ -87,6 +91,22 @@ preproc_tmpl([[Str, Phld]| Tokens], Acc) ->
 preproc_tmpl([[Str]| Tokens], Acc) ->
     preproc_tmpl(Tokens, put_head(str, Str, Acc)).
 
+%% Replace a string contains vars to another string in which the placeholders are replace by the
+%% corresponding values. For example, given "a: ${var}", if the var=1, the result string will be:
+%% "a: 1".
+replace_vars_in_str(Tokens, Data) when is_list(Tokens) ->
+    proc_tmpl(Tokens, Data, #{return => full_binary});
+replace_vars_in_str(Val, _Data) ->
+    Val.
+
+%% Replace a simple var to its value. For example, given "${var}", if the var=1, then the result
+%% value will be an integer 1.
+replace_simple_var(Tokens, Data) when is_list(Tokens) ->
+    [Var] = proc_tmpl(Tokens, Data, #{return => rawlist}),
+    Var;
+replace_simple_var(Val, _Data) ->
+    Val.
+
 put_head(_Type, <<>>, List) -> List;
 put_head(Type, Term, List) ->
     [{Type, Term} | List].
diff --git a/apps/emqx_rule_engine/src/emqx_rule_validator.erl b/apps/emqx_rule_engine/src/emqx_rule_validator.erl
index e32ec66ab..57d5eb465 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_validator.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_validator.erl
@@ -47,6 +47,7 @@
         , array
         , file
         , cfgselect %% TODO: [5.0] refactor this
+        , editable_select
         ]).
 
 %%------------------------------------------------------------------------------
@@ -84,6 +85,9 @@ validate_spec(ParamsSepc) ->
 %% Internal Functions
 %%------------------------------------------------------------------------------
 
+%% Validate editable_select first, because editable_select has enum selection.
+validate_value(Val, #{type := editable_select}) ->
+    Val;
 validate_value(Val, #{enum := Enum}) ->
     validate_enum(Val, Enum);
 validate_value(Val, #{type := object} = Spec) ->