Bulk employee update for Refresh Group Membership process - HCM Groups

Summary: Is it possible to add a specific list of multiple employees in the HCM Group Refresh Group Membership process? I've tried loading multiple names separated via commas and semicolons. And I'm attempting with the names in the standard last name, first name format. Or is there a different avenue a person can take to make a mass update for a specific list of employees in the HCM group?

It obviously works with one name, but I have a list of 200 specific employees that need updated (not every single person currently in the HCM Group, though).