RibbonDropDownButton can show a list of items inside a Ribbon button. You can hard code the items by adding a collection of menu items like so:

<r:RibbonDropDownButton Command="me:AppCommands.OtherReports">

<MenuItem Header="Cash Flow Report" />

      <MenuItem Header="Favorites Report" />

      <MenuItem Header="Spending Report" />

      <MenuItem Header="Savings Report" />

      <MenuItem Header="Credit Report" />

</r:RibbonDropDownButton>

 You can also bind the items to a data source. Let's bind the RibbonDropDownButton to a generic dictionary. First lets compose the dictionary:

Next, lets bind the ItemsSource like so:

Now that our RibbonDropDownButton’s items collection contain our dictionary, lets make sure it displayes the data correctly by adding an ItemTemplate

<r:RibbonDropDownButton Name="MyRibbonDropDownButton" Command="{StaticResource PingGroupCommand}" MenuItem.Click="RibbonDropDownButton_Click">

<r:RibbonDropDownButton.ItemTemplate>

            <DataTemplate>

                  <StackPanel>

                        <TextBlock Text="{Binding Value}" />

                  </StackPanel>

            </DataTemplate>

      </r:RibbonDropDownButton.ItemTemplate>

</r:RibbonDropDownButton>

Notice we have used {Binding Value} in order to bind the TextBlock to the Value of our dictionary. We could also use the {Binding Key} if we need to show the key.
Now that we are showing the items correctly, we can track user selection using the MenuItem.Click event. A MenuItem is actually a HeaderedItemsControl so we are going to have to base type cast it in order to get the item’s key

The end result will be a RibbonDropDownButton that can be populated from a database, XML file or any other data source.