Who influenced M1 and M2 and was influenced by a person
SELECT DISTINCT ?x0 WHERE {
?x0 a ns:people.person .
?x0 ns:influence.influence_node.influenced M1 .
?x0 ns:influence.influence_node.influenced M2 .
?x0 ns:influence.influence_node.influenced_by ?x1 .
?x1 a ns:people.person
}