Zoom a pane, then bring the others back
⇧⌘Return makes the focused pane fill the window. Press it again and the other panes come back as they were.
How to do it
- Click the pane you want to work in.
- Press ⇧⌘Return: it fills the window and the other panes are hidden, not closed.
- Press ⇧⌘Return again to bring the other panes back, with their folders and sizes as they were.
Shortcuts
⇧⌘Return
More detail in the guide: Tabs, panes, and workspaces