Ok so if you go to the pump on the right side of the pics.
1st-Follow the Pvc from the front of the pump to the 1st 3way valve, im guessing the left side is probably the main drain in the pool. (its on) whatever direction the rounded part of the valve handle is pointing that is what is off FYI. Example the first pic the in floor cleaning system is off. Second pic its on.
2nd- If you go to the right of the 1st 3way valve you get to another 3way valve. Im guessing one is for spa skimmer, and one is for pool skimmer.
if there isn't a skimmer in the spa is there a main drain? if theres a main drain, I would assume the 1st one I talked about would then be the single skimmer and the second 2 are the 2 main drains.
For the return side:
I cant tell real good from the pic but looks like theres a T before you get to the 3way valve? if so is there a valve there also?
I do agree that the cleaning system is the "spider looking thing"
the one the left of that im guessing is the spa returns cause of the check valve. which would keep the water from draining into the pool from spa when the filter is off
And assuming that there is a valve at that 1st T before the 3way valve, that's your pool returns
and yes the second pump I would say is for the spa maybe a second switch maybe labeled jets at the spa? check all breakers and make sure they are on also