Amazon purchase but I am confused on wiring.

Trying to measure the current and voltage of charge going into storage batteries being charged by solar panels.  Input for the meter is after the charge controller.  Panels output 17.12 amps so internal shunt can be used according to directions.

Voltage Input + should be to the middle screw terminal?

Common Terminal (bottom screw terminal) connected to ground of battery?

Current Input (top screw in diagram) is connected to ???  My guess is that it should also be connected to ground of battery but directions are not clear.

Any help would be appreciated.