office vs administrative unit

office and administrative unit both are nouns.

Word	Noun	Adjective	Verb	Adverb
office	Yes	No	No	No
administrative unit	Yes	No	No	No

As nouns, administrative unit is a hypernym of office; that is, administrative unit is a word with a broader meaning than office:

Other hypernyms of office include administrative body.

office (noun)	administrative unit (noun)
a religious rite or service prescribed by ecclesiastical authorities	a unit with administrative responsibilities
the actions and activities assigned to or required or expected of a person or group
a job in an organization
place of business where professional or clerical duties are performed
professional or clerical workers in an office
an administrative unit of government
(of a government or government official) holding an office means being in power