In desktop version, we can select a top-level or sub-level notebook, and right-click mouse button to add a new sub-notebook,
but for android version Joplin, following the same method can create only a top-level notebook, so is there any trick to create a sub-notebook in Android verison Joplin?
What I do is write documents in the root and then make the subfolder when I get to the desktop version. Then drag the documents into the new folder. If there is a way, other than that, I don't know of it.