Which art director was employed by M1 , employed by M2 , and employed by M3 's child
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:film.film_art_director .
?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.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent M3
}