This sounds similar to what the Rialta and LeSharo Class B Motorhome does. It is an ingeneous "origami" bathroom that folds up into a very small closet. The shower pan is permenently mounted in the center of the coach's floor. A piece of bound carpet hides it when the bathroom is "closed." To activate the full bathroom, you pick up the carpet out of the shower pan & grab the handles on the closet wall and pull the whole closet out into the center of the room, over the shower pan previously hidden in the floor. You then open the door, step inside, and flip down the panel over the toilet, and the sink, faucet, and hand held shower head appears! slip the shower head into it's wall bracket, and you're ready to go.
LeSharo Bathroom Picture
Thanks so much for the link / picture. I was going by memory! I wish it showed how it pulls out.