Need to hide action

In the Record you have option to secure related actions for groups. Go to Views and Actions Security under Security header. Click on Actions header. Click on the pencil icon at top right corner of Action to open the security configuration dialog box. You can add the permitted group for the action here. You can also configure groups from this it should not be visible using expression like not(a!isUserMemberOfGroup(username:loggedInuser(),groups:groupConstant)). 

Is this about "these groups have permission to start this action in general", or about "these groups may star the action based on some condition"?

This is what the Related Action "visibiltiy" condition is for - you can make it evaluate basically any expression! 

Additionally, you can exclude certain groups from Process Model visibility, which can work when the exclusion is a bit more concrete.  You can use both methods together and then Appian will show the Related Action only to a user who passes all checks (visibilty expression AND process model visibility).

Hi Rahul you can set up the rule like this

then if the any user if part of Group A will not able to see that action. Lets say 1 member is in multiple grps but as u specifically forbid the action for Group A members it will not able to see the action

Hi Rahul,
Use action security functionality of record to hide the related action based on conditions.