How to list /content/section/subsection1, subsection2, etc

After many hours of searching the forums, I found this: Listing nested directories

Then I did what @budparr suggested:

{{ $sections := (.Site.GetPage "section" "community").Sections }}

{{ range first 15 $sections | shuffle}}

And that shows the countries only now. I never heard of the .GetPage function. I do not see this mentioned on https://gohugo.io/variables/site/ unless I missed something.

What does this function really do? .GetPage from section called community and then get .Sections from that? I didn’t even know you could do that. Cool.