If you want to be more specific about which room is considered the 2nd or 3rd bedroom, you can do that by either renaming a room or adding a room location.
To rename a room, follow these instructions here.
You can only add a room location on an Android or iOS device. To add a room location,
- Select a room
- Select Description from the upper left corner
- Select Location and add a location such as Front Left Second Floor or whatever standard you have for describing the room
- Select the back arrow on the top left of the page