I am using the folowing method to mange my library:
http://manual.calibre-ebook.com/sub_groups.html
I want a main header of History with sub headers of American, world etc. When I created the genre History the American title appeared no problem. But when I add World it created a whole new parent group History with world as the child.
I am sure I am just missing something here. Please help.
I did History.American for the first one. Then I did Hisotry.World thinking it would go to the original parent. I would think History.American.World would put world under American.