matchmaker vs go-between

matchmaker and go-between both are nouns.

Word	Noun	Adjective	Verb	Adverb
matchmaker	Yes	No	No	No
go-between	Yes	No	No	No

As nouns, go-between is a hypernym of matchmaker; that is, go-between is a word with a broader meaning than matchmaker:

Other hypernyms of matchmaker include intercessor, intermediary, intermediator, mediator.

matchmaker (noun)	go-between (noun)
someone who arranges (or tries to arrange) marriages for others	a negotiator who acts as a link between parties