Was a art director employed by M2 's employer and employed by M1
SELECT count(*) WHERE {
?x0 a ns:film.film_art_director .
?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 ns:business.employer.employees/ns:business.employment_tenure.person M2
}