You can open multiple top-level windows, and save them all into a Lister Layout so that you can re-create them all at any time.
Within a single top-level window, you can have one or two visible folders, side-by-side, and an unlimited number of folders in tabs on either side.
You can't have 4 folders visible at once in a single top-level window, but can have two windows next to each other (two folders in each) if you want 4 folders.