I am trying to set up a booking system that comprises of 3 separate services - service 1 books a room that holds say 12 people - this works fine - service 2 works the same but allows for more people - service 3 allows more people but can only be booked if there have been no bookings for either Service 1 and 2 in that particular time slot as it requires the use of both rooms e.g - service 1 runs from 10am - 12pm and service 2 runs from  10.30 am to 12.30 pm - service 3 would then be bookable from 1pm - 3pm - I have set up shared resources that block off the time as needed so under normal circumstances this works as intended - however for service 3 all employees need to be available in order to provide this -  in testing if the employee for service 1 or service 2 is absent or has a day off Service 3 can still be booked if there is free slots for service the employee who is present available though the other cannot be booked because the employee is off - is there a way that i need to set up resources or is there a code snippet or setting that i am missing that will not allow service 3 to be booked if the employee assigned to services 1 or 2 are absent -