nadležan

1. (of an authority, person) competent; responsible; in charge
   Ko je nadležan za izdavanje dozvola? — Who is in charge of issuing permits?
   Slučaj je prosleđen nadležnom sudu. — The case was referred to the competent court.

2. (as a noun, plural) the authorities
   Nadležni još ništa nisu preduzeli. — The authorities haven't done anything yet.
3. (as a noun) the person responsible; the competent official
   Za pritužbe se obratite nadležnom. — For complaints, contact the person responsible.

The area of responsibility is introduced with za + acc.: nadležan za obrazovanje. For 'boss, one's superior' the word is nadređeni, not nadležni.