Idea and sketch:
If employee and manager information is stored in the same database table you might have to ask your universe designer to alias that table and provide universe objects for employee information and another set of universe objects to provide manager information.
Andreas’ guidance is correct. If one table is going to play multiple roles, creating an alias is the accepted approach in BusObj. Another option, if you are using Oracle at least, is the CONNECT BY PRIOR functionality. It’s a very quick way to follow a “self-referencing” chain all the way up the hierarchy.