expert vs doer

expert and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
expert	Yes	Yes	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of expert; that is, doer is a word with a broader meaning than expert:

Other hypernyms of expert include actor, worker.

expert (noun)	doer (noun)
a person with special knowledge or ability who performs skillfully	a person who acts and gets things done

expert (adjective)	doer (adjective)
having or showing knowledge and skill and aptitude
of or relating to or requiring special knowledge to be understood