Which employer of M0 and M1 did a art director found
SELECT DISTINCT ?x0 WHERE {
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x0 ns:organization.organization.founders ?x1 .
?x1 a ns:film.film_art_director
}