Hi Karl,
thank you. As far I understand you, you mean to organize that outside jAlbum, i.e. in the file system of the OS. Inside jAlbum this is not possible. Right?
Yes. jAlbum's project pane works nice for managing a single project.
http://jalbum.net/help/de/JAlbum/Explore#Projektliste
But its multi-project capabilities are pretty limited. Therefore I use it only on rare occasions.
I prefer the system's file manager for managing projects. Folder "Albums" sits in upper left corner of my desktop. Opening this folder and clicking one of its entries opens the pertaining project.
Most users I know prefer this method as they are familiar with it when opening a document. They just click the file and it will open in LibreOffice Writer, Kate or whatever is associated with the file type.
See screenshot jalbum32.png
With the file manager you can have subfolders, while the project pane has only a linear list. Links are created readily. Enter the name of the project, say
Ulli.jap and the path to its storage, say
/home/Albums/Ulli/jalbum-settings.jap and you're done.
See screenshot jalbum33.png