If htop is immensely useful for controlling the processes running via the command line then ranger is immensely useful for navigating the file system using the command line.

You will probably need to install ranger to be able to use it but once installed you can run it simply by typing the following into the terminal:

ranger

The command line window will be much like any other file manager but it works left to right rather than top to bottom meaning that if you use the left arrow key you work your way up the folder structure and the right arrow key works down the folder structure.

It is worth reading the man pages before using ranger so that you can get used to all keyboard switches that are available.