We have the ability to do this now. And I currently do this with my church app and it works wonderfully. Only certain people have access to certain parts of my app based on their title.
Here are the concept and thought process.
1.Create a new sheet called Goup Menu (This sheet will be used as an accesspoint with many doorways to various parts of your app)
2. Every user will have access to this "accesspoint, but only people with the “Key” can open the door.
3. Give all your users an extra column which decides whether or not this person has the “Key” based on their Group name. You can use "If group = Manager, “Manager”, iF group = “Supervisor”, “Supervisor” etc.
4. Create the various “Doors” in the Group menu to various parts of the app. (These are list items)
example in the group menu you may have a dooway called “Finance” and that refrences your finance sheet with the Key labeled as “Manager”
So you use referencing from the user menu and give that manager user the key to view the door that says finance.
5. The supervisor’s key is labeled “Supervisor” so they won’t match the reference so they won’t see the Finance door.
Rinse and repeat for other doors.
Hope this helps