occupier vs dweller

occupier and dweller both are nouns.

Word	Noun	Adjective	Verb	Adverb
occupier	Yes	No	No	No
dweller	Yes	No	No	No

As nouns, dweller is a hypernym of occupier; that is, dweller is a word with a broader meaning than occupier:

occupier: someone who lives at a particular place for a prolonged period or who was born there
dweller: a person who inhabits a particular place

Other hypernyms of occupier include denizen, habitant, indweller, inhabitant.

occupier (noun)	dweller (noun)
someone who lives at a particular place for a prolonged period or who was born there	a person who inhabits a particular place
a member of a military force who is residing in a conquered foreign country