You can make rooms dependent on each other meaning that one is only available it the other one is available, too.
Example: A holiday house which consits two separate apartments (Apartment1 and Apartment2). Apartment2 can be split up into two separtely bookable apartments (Apartment2A and Apartment2B). Also the complete house is for rent. To set this up you will need to set up five room in SETTINGS -> ROOMS.:
*House