What did a screenwriter that M1 and M2 employed edit
SELECT DISTINCT ?x0 WHERE {
?x0 ns:film.film.edited_by ?x1 .
?x1 a ns:film.writer .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
?x1 ns:people.person.employment_history/ns:business.employment_tenure.company M2
}