PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl: <http://www.w3.org/2002/07/owl#>  
PREFIX : <http://example.org/test#>

SELECT ?x
WHERE { 
    ?x a [
        a owl:Class ;
        owl:intersectionOf ( 
            :A 
            [
                a owl:Class ;
                owl:unionOf ( :B :C ) 
            ] 
        )
    ]
}
