Hello LLUEMSchedule,
Unfortunately this is a limitation in the current version of the Scheduling Tool. The best way to handle this situation is to create a second identical shift for the second person. The first shift will require 1 PGY-2 or -3, and the second shift will require 1 PGY-1 or -2 or -3.
I hope that helps,
Olivier Forget
Owner and Developer
MedRez.net Scheduling Tool