Which actor that M2 employed was a film producer that M3 and M4 starred
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.actor .
?x0 a ns:film.producer .
?x0 ns:film.actor.film/ns:film.performance.film M3 .
?x0 ns:film.actor.film/ns:film.performance.film M4 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}