I miss TkDesk, which I discovered many years ago when I was first trying Linux, partly because it supports unlimited splits, not just two. In fact, if I'm remembering correctly, when navigating to a subdirectory the default was just to open it in a new split. You ended up with splits containing the full path from wherever you started to your eventual subdirectory (you could scroll the view of splits horizontally once there got to be too many).

https://tkdesk.sourceforge.net/