Workspace
In Sudhaus you organize your decks with a workspace. A workspace is a tree of decks and folders. Decks and folders can both exist at the top level, or you can nest decks and folders in folders.
As a simple example you could have a folder called "Commander" that you put all of your commander decks in.
To nest things simply drag them into the level you want them at. I.e. if you wanted a deck to be in the Commander folder you would drag it into it.