。
My direct supervisor is a difficult person.
Literal
I [of-の] direct [of-の] boss [topic-は] difficult-natured is.
直属 literally 'direct affiliation' — used in Japanese corporate structures to specify the direct reporting chain, not indirect or higher-up bosses. 上司 ('superior, boss') is the standard term in business contexts. 気難しい ('difficult, particular, hard to please') is a compound i-adjective from 気 ('mood') + 難しい ('difficult').