Who was a costume designer that M2 and M3 employed
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.film_costumer_designer .
?x0 a ns:people.person .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3
}