The Backstage
is the menu that’s hidden behind the File button in the top-left corner in office.
Let’s fill the backstage with items:
<!--Backstage-->
<Fluent:Ribbon.Menu>
<Fluent:Backstage>
<Fluent:BackstageTabControl>
<Fluent:BackstageTabItem Header="New" />
<Fluent:BackstageTabItem Header="Print" />
<Fluent:Button Header="Blue" />
</Fluent:BackstageTabControl>
</Fluent:Backstage>
</Fluent:Ribbon.Menu>