Which art director employed by a company and employed by M1 was a director of M2 and M3
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.film_art_director .
?x0 ns:film.director.film M2 .
?x0 ns:film.director.film M3 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x1 a ns:business.employer
}