Filter Lookup Dropdown Based On Logged In User

Filter Lookup Dropdown Based On Logged In User

I have a field in the Application "Contractors" that is a dropdown called "Region" within the "Contractor Info" Form    

I'm using another Application "Scheduling" that uses the "Contractor Info Form" as a lookup field to input "Contractor Name"

What I need to do is to make another form (not sure if it should be in the Scheduling Application or in the Contractors Application) where I attach "Region" to a specific manager (either as their login email or User ID).  Thinking this would tie "Region" to a "User ID" of the appropriate manager.

Ultimate goal is to limit the lookup field "Contractor Name" in the Scheduling App based on the LoggedInUser to only those managers associated with the "Region" from the "Contractor Information Form"