<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:viewModels="clr-namespace:MainFrame.ViewModels">

    <Style TargetType="{x:Type TabItem}">
        <Setter Property="Tag" Value="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Window}}}"/>
        <Setter Property="Uid" Value="{Binding Uid}" />
        <Setter Property="ContextMenu">
            <Setter.Value>
                <ContextMenu>
                    <MenuItem Header="Закрыть вкладку" 
                              Command="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ContextMenu}}, 
/*Здесь не вызывается*/	      Path=PlacementTarget.Tag[{viewModels:ViewModelComands.CloseTabCommand}]}"
                    />
                </ContextMenu>
            </Setter.Value>
        </Setter> 
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type TabItem}">
                    <!-- this is the header template-->
                    <Grid x:Name="TabItemGrid" HorizontalAlignment="Stretch" Background="#FFE5E5E5" Margin="2,0,2,0">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="53*"/>
                            <ColumnDefinition Width="15*"/>
                            <ColumnDefinition Width="4*"/>
                        </Grid.ColumnDefinitions>

                        <ContentPresenter Content="{Binding Header}" />

                        <Button Name="ButtonCloseTabItem"
/*Здесь вызывается*/            Command="viewModels:ViewModelComands.CloseTabCommand"    
			/>

                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

 
namespace MainFrame.ViewModels
{
   internal class MainViewModel : ViewModel
   {

      public ObservableCollection<TabItemViewModel> Tabs
      {
         get { return Get(() => Tabs); }
         set { Set(() => Tabs, value); }
      }

      private void Initialize(StreamingContext streamingContext = default(StreamingContext))
      {
         this[ApplicationCommands.Close].Executed += (sender, args) => Application.Current.Shutdown();
         this[ViewModelComands.CloseTabCommand].Executed += (sender, args) => CloseTab(sender, args);
      }

      private void CloseTab(object sender, RoutedEventArgs e)
      {
         // ищем родительскую вкладку
         TabItem tabItem = ParentControl.FindParent<TabItem>((Control)e.OriginalSource);
         if (tabItem != null)
         {
            var select = Tabs.Where(i => i.Uid.ToString() == tabItem.Uid.ToString()).ToList();
            foreach (var item in select)
            {
               Tabs.Remove(item);
            }
         }
      }
   }
}

 
namespace MainFrame.ViewModels
{
   class ViewModelComands
   {
      static ViewModelComands()
      {
         CloseTabCommand = new RoutedUICommand("Закрыть вкладку", "CloseTab", typeof(ViewModelComands));
      }

      public static RoutedCommand CloseTabCommand { get; }
   }
}

<Setter Property="Tag" Value="{Binding RelativeSource={RelativeSource Self}}"/>

и

<MenuItem Header="Закрыть вкладку" 
          Command="viewModels:ViewModelComands.CloseTabCommand"
          CommandTarget="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ContextMenu}}, 
                                  Path=PlacementTarget.Tag}"
/>

TabItem tabItem = (e.OriginalSource is TabItem) ? (TabItem)e.OriginalSource : ParentControl.FindParent<TabItem>((Control)e.OriginalSource);