levis vs blue jeans

levis and blue jeans both are nouns.

Word	Noun	Adjective	Verb	Adverb
levis	Yes	No	No	No
blue jeans	Yes	No	No	No

As nouns, blue jeans is a hypernym of levis; that is, blue jeans is a word with a broader meaning than levis:

levis: a popular brand of jeans
blue jeans: (used in the plural) close-fitting trousers of heavy denim for manual work or casual wear

Other hypernyms of levis include denim, jeans.

levis (noun)	blue jeans (noun)
a popular brand of jeans	(used in the plural) close-fitting trousers of heavy denim for manual work or casual wear