Can I turn the water supply to the shower off here (picture)?

I posted earlier about a Ghroe shower faucet that wouldn't turn off. I managed to finally get the handle off and now I am looking at this inside the wall.

The flat head screws that are on the far sides behind this piece in the middle – are those what I should be able to turn to cut the water to this shower? Or is there another way?

My goal here is not to repair this whole thing rather than to see if I can just shut off the water to the shower so I can turn the house water supply back on and call a plumber during the week for a full repair or replace.

Thank you.