I’m not sure I understand your request correctly.
Each “Player” has to be assigned to any of the terms of the “Skills” taxonomy, which you want to match with. Do you have some sort of a primary/sub category setup?
From the image, it seems like this is sort of a primary/sub/sub/.. category setup, but I don’t know if I understood correctly.
Yes, each player can be assigned with any ‘skill’ term. My client already has some skills that are parents of other skills, but that parent/child relationship doesn’t match the one I sent you on the picture. So what I want, is to be able to make checkboxes for a group of taxonomy terms.