i got some street wires dual ring terminal hex bolt terminals that have 2 hex bolts that can accept as many as 4 rings each. 3 for sure as long as these arnt classy set screw type ones that are super thick. it will only accept 1 of those. so 3 crimp styles each for a totla of 6 rings on each battery terminal
Knukonceptz new battery terminals accepts 3 runs of 1/0 or 4awg depending on how you switch out the fittings. FTW or can always make some buss bars also a good option.
Might want to consider just mounting some sort of power distribution under the hood and have one short large gauge wire run to that. A single 1/0 1-2' long will handle what most batteries on the road could discharge