You need to either set up separate listings for all the configurations or post a note in your listing about bed usage.  This way the guest who has 7 guests and wants 7 beds books the correct reservation.  

 

1. listing#1 - one person, one bed (additional people fee for sleeping in the same bed only) 

2. listing #2 - two people, two beds (addtional people only to sleep in the same beds - so 4 people 2 beds)

3. listing #3 - 4  people, 4 beds..... extra people up to 8 total in 4 beds..... 

4. Listing #4 - 6 people, 3 beds.... 

5. Listing #5 - 7 people, 7 beds ... extra people must sleep together with these guests up to a total of 14 guests???? 

You need to come up with the exact sequence of iterations and there are multiple threads in the Forums that discuss this exact question.

 

The listings descriptions and set ups are critical to getting the right guests into the right sleeping configuration and you, as the host, control this, not the guest.  You are the person providing the beds so you need to set up the listings to create the right price and bed arrangements that suit your listing.