sense of smell vs exteroception

sense of smell and exteroception both are nouns.

Word	Noun	Adjective	Verb	Adverb
sense of smell	Yes	No	No	No
exteroception	Yes	No	No	No

As nouns, exteroception is a hypernym of sense of smell; that is, exteroception is a word with a broader meaning than sense of smell:

Other hypernyms of sense of smell include modality, sense modality, sensory system.

sense of smell (noun)	exteroception (noun)
the faculty that enables us to distinguish scents	sensitivity to stimuli originating outside of the body