What is {cast member} of {Doctor Who} that is {character role} is {Bill Potts} ?
Who plays Bill Potts on Doctor Who?
SELECT ?obj WHERE { wd:Q34316 p:P161 ?s . ?s ps:P161 ?obj . ?s pq:P453 wd:Q23908728 }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q34316> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P161> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P453> <http://wikidata.dbpedia.org/resource/Q23908728>
} 

What character did Bill Potts play in Doctor Who?