Whenever there are three or more page links to be displayed in the breadcrumbs, Confluence will use an ellipsis like this '...' and display only the topmost and lowermost page links. Clicking on the ellipsis will display the page links in between.
Note that the Dashboard and space homepage links are always displayed at the start of the breadcrumbs, and are not counted as ancestors for the purpose of this setting.
Screenshot above: Breadcrumbs
You can configure how many immediate ancestors you want displayed in the breadcrumbs when you go to the page.
To configure the number of ancestors to show in the breadcrumbs: