Re: Assigned To Customization/Restiricting Assigned to
I'm afraid that you cannot (easily) restrict the list to see only the users of the developer group.
I would recommend that you validate the selection in the Bug_FieldCanChange function of the workflow.
Use TDConnection.Customization.Users.User (NewValue).InGroup ("Developer") to know if the selected user is in the developer group. Return false (eventually after you displayed an appropriate error message) if that call returns false.
Your bet here is that users will get used to select one of the "correct" users because of the error message.