Congolese vs African

Congolese and African both are nouns.

Word	Noun	Adjective	Verb	Adverb
Congolese	Yes	Yes	No	No
African	Yes	Yes	No	No

As nouns, African is a hypernym of Congolese; that is, African is a word with a broader meaning than Congolese:

Congolese (noun)	African (noun)
a native or inhabitant of the Republic of the Congo	a native or inhabitant of Africa

Congolese (adjective)	African (adjective)
of or relating to or characteristic of the Congo region or its people	of or relating to the nations of Africa or their peoples