Example for menu with subdirectories

[LasseKrache]

Hello,

As I am new to hugo and hugo-book this is probably not an error or issue ... it is just a stupid question.

I am unable to get the menu with the correct entries with this content:

/computer
/computer/hardware

• printer.md
• scanner.md
• ...

/computer/software

/computer/software/windows

• office.md
• sap.md
• adobe.md
• ...

/computer/software/linux

• ...

I would like a menu with the entries "software" and "hardware" and beneath software the entry "windows" and so on.

What I get is a list of ALL md files in one row when I use
BookSection = '*'
I guess there is another option that needs to be set ... but which one? Can someone post an example of a configuration, which works as descibed?

Any help would be very appreciated!
Lasse