[billli]

My tests using this indicate it does not work for restricting the default screen set a smartlink action will return. This is what GC3 help advises regarding this option:

Configure Field Screen Set Access


Use this page to configure the default screen set that is used when you click the icon next to a field. This icon displays a subsequent Search page for locating records of that type (for example, locations).

Click Prevent Access Changes to prevent other users from changing the User Preference Access configuration that you are making. This prevents any other user from having the ability to change the access assignment for the branch you selected above. However, it does not prevent a user from changing the configuration of the actual object (e.g., Screen Set, User Menu, or Saved Query). If you want that level of security, you will need to modify the menu link or functional security for that object.
Choose the Query ID for the object that is represented by the field that you want to configure. For example, if you want to configure a Field Screen Set for the Search page that appears when you click next to the Source Location ID field (shown above), you would choose LOCATION as the Query ID.
Choose a Screen Set ID that controls the appearance of the Search page. Use the Content Manager to create and design custom screen sets.