Hi Graham. You can setup separate booking grids to pool availability and check multiple calendars for shared free time. This can’t be accomplished dynamically with a drop down, but that is something we have been thinking a lot about. If you are using Google calendar, you can select all the sales reps to see overlapping free time. Then you can create a booking on one of the calendars. This event could then accept additional participants of the other folks needed for the call. This is a manual way, I am not sure if anyone else would have a different approach.