question: Who was a Canadian film director whose employer employed M3 and employed M4
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.director .
  ?x0 a ns:people.person .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x0 ns:people.person.nationality ns:m.0d060g .
  ?x1 ns:business.employer.employees/ns:business.employment_tenure.person M3 .
  ?x1 ns:business.employer.employees/ns:business.employment_tenure.person M4
  }