unselfishness vs sharing

unselfishness and sharing both are nouns.

Word	Noun	Adjective	Verb	Adverb
unselfishness	Yes	No	No	No
sharing	Yes	Yes	No	No

As nouns, sharing is a hypernym of unselfishness; that is, sharing is a word with a broader meaning than unselfishness:

Other hypernyms of unselfishness include share-out.

unselfishness (noun)	sharing (noun)
acting generously	a distribution in shares
the quality of not putting yourself first but being willing to give your time or money or effort etc. for others	sharing thoughts and feelings
	having in common
	using or enjoying something jointly with others

unselfishness (adjective)	sharing (adjective)
	unselfishly willing to share with others