kitchen cabinet vs ingroup

kitchen cabinet and ingroup both are nouns.

Word	Noun	Adjective	Verb	Adverb
kitchen cabinet	Yes	No	No	No
ingroup	Yes	No	No	No

As nouns, ingroup is a hypernym of kitchen cabinet; that is, ingroup is a word with a broader meaning than kitchen cabinet:

kitchen cabinet: an inner circle of unofficial advisors to the head of a government
ingroup: an exclusive circle of people with a common purpose

Other hypernyms of kitchen cabinet include camp, clique, coterie, inner circle, pack.

kitchen cabinet (noun)	ingroup (noun)
an inner circle of unofficial advisors to the head of a government	an exclusive circle of people with a common purpose