I’ve not yet repaired any 2017 Touch bar yet, but I’m pretty sure that’s much too small to be the battery connector. I’d suggest you add a wider field picture to figure out exactly what that is. However, Apple is strongly trying their best to not let any third party repair their boards lately, they’re even preventing chips they use on their boards to be found in the market just in case a few hundred bucks can slip away from their greed chain, thus you won’t be able to find a replacement part for sale anywhere. Your best chance is to try to find a dead board on eBay and get your part from it. Or, sad but true, replace your logic board because of a 2 cents worth pure plastic part.