title_body: Within Calibre, is it possible to set a hierarchy on the series field? Calibre supports hierarchical tags, by placing a dot between the parent and the children tags, like, in example: History.Ancient History, History.Middle Ages, and so on.
  
  In the navigator panel on the left, this is displayed like this:
  
  History
  |- Ancient History
  |- Middle Ages
  
  
  I'm trying to find out it it is possible to have this feature even to fields that are not marked as "tags", specifically to the "series" field, to categorize book series in to broader cycles (useful for book series like the Videssos Cycle by Harry Turtledove, where you have multiple series belonging to the same universe).
  
  I've tried to use the dot like in the tags field, but it doesn't work.
  
  Someone knows if it is possible to do that in some way?
upvoted_answer: According to the Calibre manual, the series field, amongst many other, supports a hierarchy by using a dot between the parent and children tag.
  
  This behavior should be enabled in the options panel: