I have a leak in my shower/tub that I have not been able see where it is comming from. This is a new install I just did. I took the drywall off the closet, which I guess is OK, needed acess to the plumbing and at least it will always be there.

I have a Danze PB valve with a 4-port dirverter. I run tub, shower and hand shower off the dirverter. From the back I see nothing leaking yet the floor is soaked and you can see the water run out of the grout by the tub [I have not caulk yet]. The water must be comming from a fitting and rolling down the felt paper and then go down side of tub where it reaches the floor. This would explain why I can see any water on the backside of the paper

My guess is two things:
1] I think it is the hand shower. A brass pc threads on the nipple, this pc has o-rings on it and the finish pc slides on that then tighens with a set screw. This is a guess but could the water hit the finish mounting pc and shoot back down the hole cut in the tile, then follow the paper down to the floor?