Hierarchy of pages

The user documentation of Omeka S show a screenshot with ordered pages:

However, there is no option to declare a page as children of another (or I didn’t find it).

Could someone enlighten me?

This is the navigation hierarchy: in the menu Navigation, you can move each link as you want.

Ok I see.

So there is no way to organize pages if there are not added to the navigation.

Not really a problem of course.