sidebar to display current folder and children only

Hi,

I'm using learn2 to publish multiple books on the same website. Homepage is on different theme. Each book is in different 1st level folder (01.home 02.book-one 03.book-two 04.book-hundred etc.)

I'd like for learn2 to display contents of current folder (book) to avoid clutter (books are accessed from homepage's portfolio section).

I know I need to modify certain loop mentioned here https://github.com/getgrav/grav-theme-learn2/issues/4#issue-103684780 but I don't know which variable to put.

Any help appreciated.