Slicer - limit selection boxes

Thanks - sadly, I need something that applies only to the filter (don't want to filter things out at higher levels), but will keep looking and thinking to see if I'm approaching this wrong. 

I suppose another option is to label the tags so the ones I want to appear are at the top, and then have these inside a small window so that the prefered options appear at the top and people who do scroll down will hopefully see that there's nothing of use down the list... or to have a longer version of the list and then just hide other options behind white boxes... Neither ideal if the list is too long, but may work for me.