PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> 
PREFIX rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX owl:  <http://www.w3.org/2002/07/owl#> 

SELECT ?c1 ?c2 ?c3
WHERE {
?c1 rdfs:subClassOf _:b.
_:b owl:onProperty ?c2.
_:b owl:hasValue ?c3.
FILTER (
!isBlank(?c1)
)
}