Above (one's) bend phrase
Beyond one's knowledge or abilities.
Carrying all three suitcases was above my bend.I had Gorge bring them to my car.
Computer programming is above my bend. You should ask Jane to solve this problem because she is regarded as the leading specialist in that field.
Sorry, I can't help you. This problem is above my bend.
Be outside the ability or willingness of someone to care more about a particular person or issue
Something is more or greater than a level, or limit of one's ability to understand.
To be slightly beyond one's abilities
If you say that something is (not) your department, you mean that it's (not) your area of expertise or responsibility.