Request: display sub-notebooks when opening a notebook

When I click on a notebook, Joplin (both pc and mobile) only displays the notes that exist inside the notebook, but it does not display the notebooks that are nested inside it.

I suggest that, clicking on a notebook that has sub-notebooks inside, we should see the list of notebooks that exist inside it (ideally as "links" that allow accessing the sub-notebook by simple clicking). This would be similar to how folders and subfolders work in a file system explorer, without having to use the tree navigator on the sidebar (or the menu button on mobile).

A related request would be to add a "back" or "go to parent notebook" button, to allow navigation of the whole tree by clicking, without having to switch to the actual tree view in the sidebar. Identical to a file system explorer.

This feature applies to both the computer software and mobile app. It would be particularly useful in the mobile app, because the tree structure is not shown on screen unless you click the menu icon. It would streamline navigation through notebooks.

For example, I have a notebook with subnotebooks, and no notes in the parent notebook:
"Personal notes" with no notes but the following sub notebooks

"Cooking Recipes" with several notes
"Creative Ideas", with several notes

When I click on "Personal Notes" notebook, I get the message "No notes in here. Create one by clicking on "New Note".

The only way to see the notes in "Cooking Recipes" is to use the tree navigator on the left panel on the computer, or, requiring extra taps in the phone, clicking the menu button in the phone to reveal the tree navigator, use the dropdown arrows to navigate to the sub-notebook, and clicking again on "Cooking Recipes". This required three taps and two changes of screen, instead of a single click.

I feel it would be a natural feature to have, that once I click on "Personal Notes", I could see, on the top of the notes list, a list of the different notebooks that are nested inside it, such that by clicking on them I could navigate to them.

I would see this as a very important feature particularly in the mobile app, because not having this option slows down navigation.

I found this related post:
Request: add an option for show/hide sub notebook notes
but it requests seeing all notes in the sub-notebooks as a single list, which is not exactly the same. I don't want to see the notes inside the sub-notebooks, but rather to see the sub-notebooks themselves.

I apologise if there is a related post, I could not find it (and I was surprised).

Thank you for this fantastic software!!

I would love to hear if there is a rationale for why opening a notebook does not show a list of the notebooks that are inside.