Hello Angel,
It sounds like you may benefit from a recursive relationship in the Employee table. Employees (leaders) have child Employees. Quickbase warns you when creating recursive relationships, but they can be useful, especially in this hierarchy of Staff.
I would recommend creating a leader checkbox, to easily indicate which employees are leaders and can have child employees. You can use this checkbox in form rules to hide/show the child employee section and embedded report. I would even recommend a grid edit embedded report to select the child employees at the leader level. You would have some clean up on the form for Child employees, choosing whether to allow the selection of a leader on the child, or to hide this selection if the record is indicated as a leader record. Most likely, you want to have a clear hierarchy of Leaders and employees, not a chain of Leader>Managers>Employees>Minions. With recursion, it allows for infinite chains, and you want to set quickbase up so that it limits you to leader>Employees in the chain.
This leaves all your employees in one table, but defines a relationship that you may use in your associations table. You then have some options.
1. you can select the leader, and conditionally select an employee (based on 2 relationships to the associations table, the employee relationship conditional on the leader relationship)
2. you can select a leader on the association, and an embedded report link can show the employees related to that leader.
3. you can use the recursive relationship to define custom permission models.
There is a lot here, but let me know if it helps.