[Put the comment in answers as possible answer]
Hee Grant,
It will be probably a bit dirty but i see multiple options:
1. Can you create instead of an enumeration an reference set selector; So a new entity with an association to the object and with a boolean for which user can see what
2. You can use a widget like this https://marketplace.mendix.com/link/component/111237 and make two dropdowns and show them based on visibility
Hope this helps
Maybe you see other better options I would like to know