PREFIX p: <http://dbpedia.org/property/>

SELECT ?film1 ?actor1 ?film2 ?actor2
WHERE {
  ?film1 p:starring <http://dbpedia.org/resource/Kevin_Bacon> .
  ?film1 p:starring ?actor1 .
  FILTER(?actor1 != <http://dbpedia.org/resource/Kevin_Bacon> )

  ?film2 p:starring ?actor1 .
  FILTER (?film1 != ?film2)

  ?film2 p:starring ?actor2 .
  FILTER(?actor2 != <http://dbpedia.org/resource/Kevin_Bacon> )
}