Which film producer did M1 's writer 's employer employ and M2 's producer employ
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.producer .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x2 .
?x1 ns:business.employer.employees/ns:business.employment_tenure.person ?x3 .
?x2 ns:film.producer.film|ns:film.production_company.films M2 .
?x3 ns:film.writer.film M1
}