As you view the document, bookmarks can be added to allow you to quickly return to that specific spot within the content. To add a bookmark to the current page, click the bookmark button.
Additionally when returning to a document, the viewer will automatically navigate to the last page you have viewed.
To quickly find your bookmarks, select the Grid View button in the lower left corner of the screen.
Grid View Button
The pages you have marked with a bookmark will be visible within the "Grid View." Select the page to navigate to your bookmark and return to the full screen view.