The Account Owner can access My Account to limit the sharing capabilities for Group Admins and Standard Users. The available options are:
Standard Users & Group Admins can share Forms with all Users – selected by default, this means that Group admins and Standard Users from a Group can find and share the Form with Users from other Groups as well.
Standard Users & Group Admins can share Forms only within their Groups
This will let Group Admins and Standard Users share Forms/Folders only with the Users from their own Group. They will only see the Users from their own Group in the list of sharing candidates.
Standard Users & Group Admins can’t share Forms
This blocks them from accessing the sharing functionality. With this enabled, no Group Admin or Standard User will be able to access the sharing interface from My Forms.
Important Note: The Account Owner and Super Admins are not impacted by these sharing preferences, as they can always share Forms and Folders with all Users from the account. At the same time, Group Admins also can still manage Form and Folder Access from the Users section, under Set Permissions.