SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/relatives> <http://dbpedia.org/resource/Nick_Williams> . ?x <http://dbpedia.org/ontology/relative> ?uri . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/RugbyPlayer>}
What are the relatives of the rugby player one of whose relatives is Nick Williams?
SELECT DISTINCT ?r WHERE { ?u property:relative ?r . ?u rdf:type ontology:Rugby_Player . ?u property:relatives resource:Nick_Williams }
Sonny Bill Williams, Nick Williams
The relatives of the rugby player whose one relative is Nick Williams are [Sonny Bill Williams, Nick Williams].
Relatives of a rugby player whose only relative is Nick Williams are [Bill Williams, Nick Williams].