Who was a screenwriter 's actor 's child 's sibling
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x1 .
?x1 ns:people.person.parents|ns:fictional_universe.fictional_character.parents|ns:organization.organization.parent/ns:organization.organization_relationship.parent ?x2 .
?x2 ns:film.actor.film/ns:film.performance.character ?x3 .
?x3 a ns:film.writer .
FILTER ( ?x0 != ?x1 )
}