The shunt is mounted near the battery. The monitor can be mounted where you like. There is a control wire that runs from the shunt to the monitor control.
I use the Victron BMV-712, as it provides bluetooth connectivity and a smart phone app which makes monitoring much easier.
As far as how to run the wire from the shunt to your desired monitor location, I can tell you what I did on my trailer, but that likely won't help much on yours.
Let me know if you have any questions and I'll do my best to answer.
2019 Cougar Half Ton 26RBSWE - "Bertha"
2019 GMC Sierra 3500 Denali HD 6.6L Duramax TD, CC, 4WD, DRW - "Mr. Beefy"