1. "But that list is in the manager table and since you can't be your own manager, the two records aren't linked."
Is that a necessity? I understand that in real life a manager can't manage themselves, is there a workflow-related reason why they can't be in your app?
2. "The Merge field can't be a user or a formula field."
Mirror the 'manager' field with a 'group' field, which you can keep on another table if you like. Basically build out another Manager table but with Managers and Employees in the same pool, and assign them to groups which can be named arbitrarily or after the managers themselves. Basically the same as #1 but with more work, but the same functionality.
