Were M1 and M2 produced by a employer of a art director
SELECT count(*) WHERE {
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
?x1 a ns:film.film_art_director .
M1 ns:film.film.produced_by|ns:film.film.production_companies ?x0 .
M2 ns:film.film.produced_by|ns:film.film.production_companies ?x0
}