Select items for reference they are not in a list

[Jean_Pierre_Traets]

Dear @Franko_Hoffmann-Samaga, welcome to the community!

I recommend to post a dummy copy of your doc, for the community to check the problem.

You might like also this related post for inspiration:

Hotel room management / inventory of available rooms

Thanks. I’m trying to flag a booking if any one of the dates in the booking range will put me over the inventory of rooms. See the “Guest Services” view. Right now I can select a date to see the sum of rooms booked on a particular day, and reservations active on that day are highlighted in blue. I’d love to be able to have conditional formatting that highlights an entry in the table when any of the days in the reservation range puts the sum of rooms occupied over 50.