Suppose you hire one of the world's leading heart surgeons only to employ them with bookkeeping or billing at your hospital. You may even be paying a wage that is commensurate with what other heart surgeons make--and he or she probably hired on thinking that heart surgery was what they'd be doing. But you stick them in billing.
I once heard a term for this from a friend in the US Army (I've lost contact and anyway I can't remember exactly whom) where he told me this was common practice. You take a commissioned office who has decades of training and lots of subject matter expertise in some way that might actually, say, help the army if they were smart about it--but they will stick them in charge of filing reports for some outpost or station. Forever.
I'm looking for a short phrase or a single word rather than the using a paragraph or two to explain this concept. For example the army guy said something like: "They had him doing _." (i.e. _ = "a task or job that was far below his training and capabilities and that essentially anybody could do with minimal training (say under two years) and that is a shame".)
EDIT: To be clear I want to say that this happens not ONLY to military folks, or people who are near retirement but also to mid-career people who are civilians.