You can set the Quick Launch to display a tree view to provide a hierarchical view of your site and subsites. With a tree view you can expand or collapse the branches to see more or less of your content.
Display the Tree View of your site in the Quick Launch
This procedure requires you to be the owner of the site or a user who has design permission for the site.
Navigate to the site for which you want to display the Site Hierarchy in the Quick Launch.
Click Settings , and then click Site settings.
On the Site settings page, in the Look and Feel section, click Navigation Elements or Tree view.
On the Navigation Elements or Tree view page, in the Enable Tree View section click Enable Tree View.
The Site Hierarchy displays in Quick Launch.