Here's the deal. You have two main options: Use one compressor, and place it first in the chain, between the bassvi and the splitter box. Or use two compressors, each on the separate legs after the splitter, before the amps.
If you can find a used TC Electronic Nova Dynamics, it was actually two compressors with two independent sets of inputs and outputs, in one pedal housing.
You can use pretty much any compressor on a bassvi, but of course a comp that doesn't work great on bass will not bring out the bassy qualities of the bassvi. The reason to choose a dual-band comp is because it compresses the lows and the highs separately, so peaks in the lows won't cause the highs to get sucked down.
For a dual-band that is simple and not crazy expensive, get a used EBS. There are cheaper ones like the Ashdown, but I'm not a fan.
All that said though, I would more strongly recommend you get two compressors, one for each post-split path. You could use any of the micro comps like the Mooer on the "guitar" path, and then a more bass-friendly pedal like the Boss LMB-3 on the "bass" path. You might be able to pick up both of them used for under $100 total. A micro sized one that I like for bass is the Fairfield Accountant.
Regarding complexity, number of knobs, etc., you'll get the best results if you take the time to learn how to set the various controls on a compressor, how they work, rather than just hoping for plug-and-play easy. Many people who hope to get good sound on bass from a comp that only has two knobs come away disappointed.