question: Which country of nationality of M2 was a employer of M0 and M1
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 ^ns:people.person.nationality M2 .
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person M0 .
  ?x0 ns:business.employer.employees/ns:business.employment_tenure.person M1
  }