Reference > Ribbon Tabs and Dialogs > The Project Tab > Project

This option displays a list of the bookmarks in your current project and allows you to add new bookmarks. Bookmarks mark topics, not positions within topics. You can only add one bookmark to any one topic.

You can jump to the bookmarks by selecting them in the list.

To create a new bookmark just select Bookmark Current Topic. By default the topic title is used as the bookmark title but you can change this if you want.