Sidebar with different directories and pages


I am new to using VuePress and am finding it good so far, but wondered if someone can assist me with something sidebar related (probably simple, but I have not been able to do it on my own).

I am able to have pages displayed in the sidebar, from the current directory. However not from other directories.

To explain, I will use the VuePress Community site as an example:

On the above URL’s page, are 2 main headings: Plugins and Tools. I suppose that each of these headings, is a different directory, containing the files (pages) under these headings.

How do I get my sidebar to appear like this? So far, all I have been able to do is, get the files (pages) from the current directory listed under a single heading on each page. I have not been able to get files from other directories to appear in the same sidebar.

Thanks in advance.