Did M3 employ a costume designer and employ a editor of M1 and M2
SELECT count(*) WHERE {
?x0 a ns:film.film_costumer_designer .
?x1 ns:film.editor.film M1 .
?x1 ns:film.editor.film M2 .
M3 ns:business.employer.employees/ns:business.employment_tenure.person ?x0 .
M3 ns:business.employer.employees/ns:business.employment_tenure.person ?x1
}