What was a film producer that M2 's writer was employed by and M1 was employed by
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.producer .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person ?x1 .
?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1 .
?x1 ns:film.writer.film M2
}