Pages, Links, Reports, and Dashboards can be set to open in a new browser window. Once the Widget is in the navigation, edit its options. Within the editing panel is a field entitled “Link Target”. Choose New Window and the pages will open in a new browser window.
There is not a way to force the link to open in a new tab within the user’s browser. This option is controlled locally, by the user’s browser. Many users have their browsers set to open new windows as a tab.
For more information about the button’s setting options, check out the “Editing the Button” section of this guide.