Looking for an idiom meaning "this is not relevant to you"

I'm looking for an idiom which is the opposite of "falls under your umbrella" or "up your ally".

For example:

I noticed you are the head of IT at ACME. Until recently, I would have thought that reducing manufacturing cost operations is _____ [idiom for "not relevant for a person at your position"].

You could negate the idioms you provided in the question: "doesn't fall under your umbrella", "not up your alley". Many idiomatic responses would be prefaced with a negation:

• They don't enjoy it: "not your cup of tea"
• They haven't seen it before: "not your area of expertise," "not your wheelhouse"
• It's beyond them: "out of your depth", "over your head", "beyond you" (note: even if meant neutrally these will generally sound condescending)
• It's something that they don't (or shouldn't, or don't want to be forced to) have responsibility over: "above your pay grade"
• Tangentially referencing a related subject that they don't know about or aren't interested in: "But that's a whole different kettle of fish"