A bit beyond (one's) ken phrase
Something is more or greater than a level, or limit of one's ability to understand.
What they are talking about is a bit beyond my ken.
This matter is a bit beyond my ken.
Be outside the ability or willingness of someone to care more about a particular person or issue
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.
Beyond one's knowledge or abilities.