Permission Set Assigned Users Page

From the Assigned Users page, you can view all users who are assigned to a permission set, assign more users, and remove user assignments.
Available in: Salesforce Classic (not available in all orgs) and Lightning Experience
Available in: Essentials, Contact Manager, Professional, Group, Enterprise, Performance, Unlimited, Developer, and Database.com Editions

User Permissions Needed
To view users that are assigned to a permission set: View Setup and Configuration

To view all users who are assigned to a permission set, from any permission set page, click Manage Assignments. From the Assigned Users page, you can: