<MenuItem Header="Удалить"  Command="{Binding }"/>

<TreeView.ItemTemplate>
                <HierarchicalDataTemplate ItemsSource="{Binding Path=IdGoodEntityCollection}">                    
                    <TextBlock Text="{Binding Path=Name}"/>                     
                    <HierarchicalDataTemplate.ItemTemplate>
                        <DataTemplate>
                            <Border Margin="5" BorderThickness="1" BorderBrush="SteelBlue" CornerRadius="4" MinWidth="120">                               
                                <Border.ContextMenu>
                                    <ContextMenu>
                                        <MenuItem Header="Удалить"  Command="{Binding ????????}"/>                  
                                    </ContextMenu>
                                 </Border.ContextMenu>
                            </Border>                                                     
                        </DataTemplate>
                    </HierarchicalDataTemplate.ItemTemplate>
                </HierarchicalDataTemplate>                
            </TreeView.ItemTemplate>   
            <TreeView.ItemContainerStyle>
                <Style>
                    <Setter Property="TreeViewItem.IsExpanded" Value="True"/>
                </Style>
            </TreeView.ItemContainerStyle>
        </TreeView>eeView>