Hello @L127,
In the same listing, it's not possible to charge per room, but it is possible to charge per guest.
If you list it as two bedrooms, then two people can use both rooms. You can set a base price for two guests and charge more for any additional guests, so four guests will pay more than two guests, but they will still use both rooms in both cases.
consider exploring the demand for your property. Another option to consider is setting a price for four people (two rooms) and not worrying about it anymore. Two people or four people pay the same. But this way, you might miss some reservations.