Who was employed by M1 's producer , employed by a film producer , and employed by M2 's employer
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x2 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x3 .
?x1 ns:film.producer.film|ns:film.production_company.films M1 .
?x2 ns:business.employer.employees/ns:business.employment_tenure.person M2 .
?x3 a ns:film.producer
}