This is how I read it. I could be wrong. Its difficult without more process info.
The primary pressure control is coming from PIT 0281 acting on valve PV-0281. An increasing signal from PIT-0281 Opens PV-0281. The PV is input into the two Arithmetic blocks.
FY-0282 Compares flow FI-0282 with pressure and calculates a predictor, or look ahead indicator signal
LY-0281B compares pressure with level indicator LIT-0281, calculates signal going to Level controller LC-0281. "Reverse" means LC's output decreases with increasing input, or increases with decreasing input.
LY-0281A converts electric signal to pneumatic signal, which is summed and sent to the flow controller FC-0281 as a Setpoint.
FC-0281 compares current flow with its Setpoint and moves FV-0281 into position. Valve movement will be opposite to FIT-0281's input signal, increasing signal closes the valve.
So, it appears to be controlling pressure immediately in the instant and adjusting flow in attempt to lessen the magnitude of the next pressure adjustment.
Its up to you to ensure the above logic makes sense to the process.
Thanks, corrected now.