I take it you have the L shaped front end. We have not had that model but have had two caravans with similar front lounges but never photographed the cushions made up as a bed. The layout works well during the day but the beds can be hard work.
I am afraid we found it trial and error getting in right, but we settled on the back rest from the side under the pillows, with the main seat bases in the middle and the front back rest under the feet. This gave only one join under us when sleeping and worked for us. Hope it helps.