[soybalm]

If something is clearly in a different frequency you can accent that instrument a little. You are going to affect all instruments that share that frequency so it takes a lot of trial and error.
There's a great tool by Waves called Trans X. That can work as a multiband but I used the wide band mode on a board mix where the drums were way too loud and dry. By lowering the threshold, turning up the sensitivity, and messing with the attack, I was able to tame the attack of the drums and push them back into the mix and at the same time, picked up mic bleed for some ambience at the same time. There was a lot of perfect circumstances in that situation for that to work. Be careful. There are other brands of transient compressors.