Element-to-Element binding inside a DataTemplate

I have a FlipView control named

imageFlipview

which resides under the DataTemplete of its parent FlipView named

flipView

I have a control which is the sibling control of imageFlipView named

imageIndicator

Now, the imageIndicator requires Element-to-Element binding, but is not working inside the DataTemplate. Here is the code

<FlipView
            x:Name="flipView"
            AutomationProperties.AutomationId="ItemsFlipView"
            AutomationProperties.Name="Item Details"
            TabIndex="1"
            Grid.RowSpan="2"
            ItemsSource="{Binding Source={StaticResource itemsViewSource}}"><FlipView.ItemContainerStyle><Style TargetType="FlipViewItem"><Setter Property="Margin" Value="0,137,0,0"/></Style></FlipView.ItemContainerStyle><FlipView.ItemTemplate><DataTemplate><UserControl Loaded="StartLayoutUpdates" Unloaded="StopLayoutUpdates"><ScrollViewer x:Name="scrollViewer" Style="{StaticResource HorizontalScrollViewerStyle}" Grid.Row="1"><StackPanel Orientation="Vertical" Grid.Column="0" Loaded="StackPanel_Loaded_1"><TextBlock FontSize="30" FontFamily=" Tahoma" FontWeight="Normal" Text="{Binding Title}" TextWrapping="Wrap"/><FlipView x:Name="imageFlip" Loaded="imageFlip_Loaded_1" Visibility="Visible" Margin="0,0,0,10" VerticalAlignment="Top" Height="515" ><Image x:Name="image1" Width="400" HorizontalAlignment="Left" Margin="0,0,0,10" Stretch="Uniform" Source="{Binding ImagePath1}" VerticalAlignment="Top"/><Image x:Name="image2" Width="350" HorizontalAlignment="Left" Margin="0,0,0,10" Stretch="Uniform" Source="{Binding ImagePath1}" VerticalAlignment="Top"/><Image x:Name="image3" Width="300" HorizontalAlignment="Left" Margin="0,0,0,10" Stretch="Uniform" Source="{Binding ImagePath1}" VerticalAlignment="Top"/><Image x:Name="image4" Width="250" HorizontalAlignment="Left" Margin="0,0,0,10" Stretch="Uniform" Source="{Binding ImagePath1}" VerticalAlignment="Top"/></FlipView><callisto:FlipViewIndicator x:Name="imageIndicator" FlipView="{Binding ElementName=imageFlip}"/></StackPanel></ScrollViewer></UserControl></DataTemplate></FlipView.ItemTemplate></FlipView>

Any Help will be appreciated