business deal vs dealings

business deal and dealings both are nouns.

Word	Noun	Adjective	Verb	Adverb
business deal	Yes	No	No	No
dealings	Yes	No	No	No

As nouns, dealings is a hypernym of business deal; that is, dealings is a word with a broader meaning than business deal:

business deal: a particular instance of buying or selling
dealings: the act of transacting within or between groups (as carrying on commercial activities)

Other hypernyms of business deal include dealing, transaction.

business deal (noun)	dealings (noun)
a particular instance of buying or selling	the act of transacting within or between groups (as carrying on commercial activities)
	social or verbal interchange (usually followed by `with')
	mutual dealings or connections or communications among persons or groups