OK, once again I searched through Calibre options, this forum and the Internet and found no solution. Here is the problem:
Let's say I have a sci-fi novel and a sci-fi short story in my collection. In my custom #genre column I classify them as Novel.Sci-fi and Short Story.Sci-fi respectively. This creates the following hierarchy in my Tag Browser:
The problem is Calibre treats both Sci-fi child items as two different genres and as a result shows only one book in each:
instead of the more desirable:
This is understandable, considering how the hierarchy is created, but is there a way around it? Please mind, I'm using Calibre v3.48.