The sample pages use Property:Located in, for example the Berlin article states the fact located in::Germany. If you want to also show this information here in the article for the object of the relationship, there are several ways to do this:
{{#ask: [[Located in::{{FULLPAGENAME}}]] |intro=Things located in {{PAGENAME}}:_ |link=all }}
Things located in Demo:Germany: Demo:Berlin, Demo:Cologne, Demo:Frankfurt, Demo:Munich, Demo:Stuttgart, Demo:Würzburg
Some pages may not directly state that they are located in Germany, and only state they are located somewhere that in turn is located in Germany. To find things located in things located in Germany, you have to nest a subquery:
Note that this does of course not realise true transitivity, but only a limited number of steps along the property «located in».