What film producer employed M1 , M2 , and M3
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.producer .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M3
}