Airbnb does not allow you to transfer your booking to another room. It is also not possible in the BedBooking application.
There is an option to suggest a listing change to a guest within an existing booking. The host can propose to a guest any other listing on the same Airbnb account, this booking alteration request can be recommended / sent to the guest using the booking alteration flow on Airbnb, but it’s up to the guest to accept or deny the alteration request. Only if guest accepts such booking alteration request, booking will be tight to a new listing proposed within booking alteration request.