OP amp circuit -- current measuring
You should ask your hardware team to provide you the transfer function (ADC voltage as a function of current). This is an entirely reasonable request and better than asking a bunch of strangers on the Internet. 

R42 adds an offset of 454mV to the amplifier non-inverting input, which is multiplied by 11 (5.00V  out at zero current) as seen at the op-amp output. That op-amp output voltage decreases by 1V/A of load current. The ADC sees half the op-amp output voltage. 

So, my take on the transfer function is: 

\$V_{ADC} = 2.5V - 0.5\cdot I_{LOAD} \;\;\; (0 \le I_{LOAD} \le 5A )\$. 

Which you can easily re-arrange to find the load current given the ADC reading and ADC reference voltage. 

It's a pretty straightforward (if sloppy in terms of potential accuracy) circuit but it's not your job to reverse-engineer their chum bucket of a design.