costumier vs clothes designer

costumier and clothes designer both are nouns.

Word	Noun	Adjective	Verb	Adverb
costumier	Yes	No	No	No
clothes designer	Yes	No	No	No

As nouns, clothes designer is a hypernym of costumier; that is, clothes designer is a word with a broader meaning than costumier:

costumier: someone who designs or supplies costumes (as for a play or masquerade)
clothes designer: someone who designs clothing

Other hypernyms of costumier include couturier, designer, fashion designer.

costumier (noun)	clothes designer (noun)
someone who designs or supplies costumes (as for a play or masquerade)	someone who designs clothing