How did I create these notebooks below a notebook

[Silvia Hagen 2]

Hello

Attached is a screenshot. I cannot duplicate what I have created earlier.

What i want to create is like the Notebook "Kunden" where I created subfolders for different customers. I want to do the same with "Coachings"

I want a Notebook "Coachings" and then have several subfolders for different clients. When I try to create this now, it creates a Notebook Stack and puts my "Coaching" below this. That is not what I want.

Any hints appreciated.

Thanks Silvia

 

[Silvia Hagen 2]

I have received the help that I needed from a friend, so consider this request as solved. Thank you. Silvia