What is {position held} of {Umar ibn Al-Khattāb} that is {start time} is {634-0-0} ?
Which was the designation of Umar ibn Al-Khattab during 634-0-0?
What position did Umar ibn Al-Khattab hold starting in 634-0-0?
SELECT ?e WHERE { ?n property:start_time ?s . resource:Umar property:position_held ?n . ?n property:position_held ?e . FILTER ( CONTAINS ( ?s , '634-0-0' ) ) }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q8467> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P39> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P580> <634-0-0>
} 

SELECT ?obj WHERE { wd:Q8467 p:P39 ?s . ?s ps:P39 ?obj . ?s pq:P580 ?x filter(contains(?x , '634-0-0')) }