Normally, I launch jupyter from a new bash terminal:
~$ jupyter notebook
and then navigate down the tree to the files I want to wo
As explained in https://github.com/ipython/ipython/issues/7751, it is not possible to navigate to the parent directory for security reasons:
The kernel might not be python, nor on the same machine than the server, nor do you need a running kernel to use server API(s).
If you want, you can ask for more information in the aforementioned GitHub issue.