Some services require more than one staff member, for example: a couple's massage or group training with multiple coaches. So it's helpful to be able to assign multiple staff to a single service.
How to Assign Multi-Staff to a Single Service
In order to assign multiple staff, on your portal, first go to Staff, then create a new staff user to represent the staff members you need

Then go to Services and create a service that will be delivered jointly by the two staff members above

When a customer books the joint service, manually block the time in both staff members' personal calendars. You can easily block time in personal calendars by clicking and dragging your mouse, then input your note details in the pop-up modal:
This way, multiple staff members can be booked, blocking the available time for the booking - allowing your staff to collaborate on a service.