[Forms&Workflows] User picker, Filter to roles user picker based on role

Currently, in a user picker such as the AssignedTo field, it is possible to select Roles, User and Both. Additionally, it is possible to filter to specific users or to specific roles.

We would like to request to make change these in a transition.
-> In StateA only users of RoleA can be selected.
-> In Approval only users with role Approver can be selected.

That would really help coordinate in large projects with hundreds of users and different assignees throughout the different states.