Service that uses all staff members

I need to be able to create a service that fully books out a venue for a time slot.

I have a selection of services setup that have the option of 5 staff members that can be auto assigned. All available for the same time slots (1hour). So we can run 5 bookings at the same time using 5 staff members.

However i need a single service that can take up ALL the staff members for that hour booking.
Therefor making it unable for another user to book a service for that time slot. (as all the staff members are busy with the one booking)

"Full Venue booking - 1 Hour"
Assigns itself to all the staff members for that selected time.

Thank you