Creating Many Relationships from One Parent Table

I would have to see / know more about your application structure, but it sounds like you have multiple tables to manage similar items - people. If this is the case, I would ask why you feel this is necessary and encourage you to limit it to 1 table. If you simply need to see a different list of people in drop-downs, you can control that through reports without the need to have separate tables for Professors, Supervisors, Donors, etc. Even if you need to capture different information for each role.