Connecting two batteries-one using the shunt, one not

If I want to have a backup battery for my trolling motor and use a switch to swap between the two, and only one battery would be using the shunt as the other would already have a bluetooth app, can I do this? To explain in more detail, I see the positive connections of each battery connecting to the switch along with the positive of the trolling motor. In order to use the switch I would need a bus bar for the negative, and this is where I am uncertain. I am thinking the negative on the battery without bluetooth that I want to monitor with the victron shunt will connect to the battery minus on the shunt. I am then thinking the trolling motor minus, the minus on the battery with bluetooth built in, and the load minus on the victron shunt must all be connected to the buss bar for the minus connections. Does this seem correct and do you foresee any issues doing it this way? Thanks in advance.

Your write up seems OK, wire from monitored battery negative to battery side of shunt, wire from system side of shunt to bus bar. No other connections to the battery or shunt.

See Correct shunt wiring

Thank you appreciate the advice and confirmation.