Example of how to filter hiring manager list to only show managers (and not all employees)

Summary

Does anyone have examples of how to filter the hiring manager list to show managers only

Content

We are looking to reduce the list of employees returned when adding a hiring manager to a requisition in ORC.

I think I can use an EL Expression on the Hiring Manager field to have it return only managers.  Unfortunately, I can't find my notes regarding the syntax to do so.  Anyone have any examples of ways to filter employee lists like this? 

Thank you.  

Version

19C