[commands] Properly set group parent for hybrid commands in cogs

discord/ext/commands/cog.py

@@ -292,7 +292,8 @@ class Cog(metaclass=CogMeta):
             elif self.__cog_app_commands_group__:
                 if hasattr(command, '__commands_is_hybrid__') and command.parent is None:
                     # In both of these, the type checker does not see the app_command attribute even though it exists
-                    command.app_command = command.app_command._copy_with(parent=self, binding=self)  # type: ignore
+                    parent = self.__cog_app_commands_group__
+                    command.app_command = command.app_command._copy_with(parent=parent, binding=self)  # type: ignore
                     children.append(command.app_command)  # type: ignore
 
         for command in cls.__cog_app_commands__: