Not sure of your model but here is what I have and I think it is pretty much standard.
I have a 3731FL, L/R up front and B/R in the rear. Three TV's, L/R, B/R and outdoors (haven't used that one).
There are Three cable inputs in the convenience center, Sat1 Sat2 and cable.
It your are using the antenna and getting over the air stations you want the booster in your B/R turned on (led on ). If using cable connect to the cable connection in the cnv/ctr and turn the booster off.
I'm thinking your connections marked L/R and B/R are satellite inputs. I tried Dish service with a King Tailgater but never really had much success with it. Seems there are too many splitters for that set up. I had to run the cable in through the window and connect directly to get it to work at all. It's possible the way yours are marked you may have fewer splitters in your rig.
I have since connected Fire Sticks to both TV's and just stream all our content now. Works fine.
2017 Lariat F-350 FX4, CC, SB, 6.7 PSD 4WD
2018 MONTY 3731FL, Residential Refer