question: Which actor whose employer was acquired by M2 and M3 and acquired M4 directed M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:film.actor .
  ?x0 ns:film.director.film M1 .
  ?x0 ns:people.person.employment_history/ns:business.employment_tenure.company ?x1 .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M2 .
  ?x1 ns:organization.organization.acquired_by/ns:business.acquisition.acquiring_company M3 .
  ?x1 ns:organization.organization.companies_acquired/ns:business.acquisition.company_acquired M4
  }