@Olga464,
If you mean a guest booked 1 room for more then 1 person:
The main guest (the person booked) is responsible and can be approached when other people in the party make trouble.
If you mean more then 1 room in a house is occupied by 1 guest:
They all are individual bookings, so not "a team". When it comes to sharing facilities they somehow have to respect each other and could indeed lead to some trouble. There is also something like "group-dynamcs", but the host should be firm and not bend for such processes.
This type of renting (more rooms in 1 house, but not living there myself) is my situation, but i allways managed to solve problems by talking to people individual. Do not go into discussions with "the group".
best regards,
Emiel