Who was employed by M1 and M2 and was employed by a country of nationality of M3 and M4
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 M1 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M2 .
?x1 ^ns:people.person.nationality M3 .
?x1 ^ns:people.person.nationality M4
}