question: Who was employed by a film director 's employer , employed by a company , and employed by M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x2 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M1 .
  ?x1 ns:business.employer.employees/ns:business.employment_tenure.person ?x3 .
  ?x2 a ns:business.employer .
  ?x3 a ns:film.director
  }