Shower faucet leaking near hose connection

[Rob Culver]

Hello all,
Has anyone experienced leaking in the shower in the area where the hose connects to the shower spout in the middle? My leak occurs as I lift up the spout in order to make the water come out to the shower rather than the two faucets below. The water then sprays out to the side. More specifically, if you look at the close in picture it seems to be coming out of the oval area directly to the top of the spout in the middle.

I removed the faucet handles as you can see from the attached picture and then removed two screws from the underside near my hand in one picture. The black enclosure appears to be a top and bottom piece on either side of my thumb. But the top piece does not want to separate from the bottom piece easily. It looks like I shouldn't need to unscrew the two white pieces in the picture to get the top black piece off, should I? Just wanted to check with others who may have had this problem that the black part really is two separate pieces and I should be able to split them.

If I can remove the top black piece, that should allow me to get a better view of where the leak might be coming from below.
Thank you in advance for any guidance that anyone can provide!