WPF binding child controls DataContext to HierarchicalDataTemplate ItemsSource item

Question

I have a collection of Barcodes that contains a collection of Positions. How do I set the DataContext of a custom control to a Position item in the collection?

    <TreeView ItemsSource="{Binding SelectedPlate.Barcodes}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Positions}"
                                  DataType="{x:Type ControlViewModels:BarcodeViewModel}">

                <TextBox Text="{Binding Code}"/>

                <HierarchicalDataTemplate.ItemTemplate>
                    <DataTemplate>

                        <!--The Custom Control that needs to bind to the Position item-->
                        <ControlViews:PositionControl DataContext="{Binding}"/>
                        
                    </DataTemplate>
                </HierarchicalDataTemplate.ItemTemplate>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>

    </TreeView>