Who was employed by a production company 's child , employed by M1 and M2 , and employed by M3
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 .
?x0 ns:people.person.employment_history/ns:business.employment_tenure.company M3 .
?x1 ns:people.person.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent ?x2 .
?x2 a ns:film.production_company
}