Basically use tabs under per-department info to switch between "All" and specific jobs. Make a catch-all "Other" pseudo-department and stuff varied things into that.
One issue though is that "at a glance" aspect goes away... but at the same time it's kinda lost when there's a few dozen different leaderboards. And when a specific person's leaderboard is queried, could put the position into title of the tab (so like, Chemist - #1, Janitor - N/A)