<Expander Style="{StaticResource MyExpander}" DataContext="{Binding Item}" MaxHeight="280" 
                          IsExpanded="{Binding Converter={StaticResource Collapsed}, Path=Collapsed, ConverterParameter=1}">
                    <ListBox ItemsSource="{Binding Item}" Style="{StaticResource StyleListSelected}" IsSynchronizedWithCurrentItem="True" />
                </Expander>

                    <Expander.IsExpanded>
                        <Binding Converter="{StaticResource Collapsed}" Path="Collapsed" ConverterParameter="1">
                            <Binding.RelativeSource>
                                <RelativeSource Mode="FindAncestor" AncestorType="{x:Type Expander}" AncestorLevel="1"/>
                            </Binding.RelativeSource>
                        </Binding>
                    </Expander.IsExpanded>

IsExpanded="{Binding Path=Collapsed, RelativeSource ={RelativeSource Mode= FindAncestor, AncestorType={x:Type Expander}}, Converter={StaticResource Collapsed}, ConverterParameter=1}"

IsExpanded="{Binding Path=DataContext.Collapsed, RelativeSource ={RelativeSource Mode= FindAncestor, AncestorType={x:Type Expander}}, Converter={StaticResource Collapsed}, ConverterParameter=1}"

Public Class ConverterBoolean
    Implements IValueConverter
    Public Function Convert(ByVal value As Object, ByVal targetType As Type, ByVal parameter As Object, ByVal culture As Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.Convert
        If IsDBNull(value) Then
            Return False
        Else
            Return CInt(value) = Integer.Parse(parameter.ToString())
        End If 
    End Function

    Public Function ConvertBack(ByVal value As Object, ByVal targetType As Type, ByVal parameter As Object, ByVal culture As Globalization.CultureInfo) As Object Implements System.Windows.Data.IValueConverter.ConvertBack
        Return If(value.Equals(True), parameter, Binding.DoNothing)
    End Function

Public Class MyClassItems
    Implements INotifyPropertyChanged
    Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
    Private mCollapsed As Integer = 0
    Private mItem As New ClassItem
    Private mItem1 As New ClassItem
    Private mItem2 As New ClassItem
    Private mItem3 As New ClassItem

    Public Property Collapsed As Integer
        Get
            Return Me.mCollapsed
        End Get
        Set(ByVal value As Integer)
            Me.mCollapsed = value
            Me.OnChanged("Collapsed")
        End Set
    End Property
    Public Property Item As ClassItem
        Get
            Return Me.mItem
        End Get
        Set(ByVal value As ClassItem)
            Me.mItem = value
            Me.OnChanged("Item")
        End Set
    End Property
    Public Property Item1 As ClassItem
        Get
            Return Me.mItem1
        End Get
        Set(ByVal value As ClassItem)
            Me.mItem1 = value
            Me.OnChanged("Item1")
        End Set
    End Property
    Public Property Item2 As ClassItem
        Get
            Return Me.mItem2
        End Get
        Set(ByVal value As ClassItem)
            Me.mItem2 = value
            Me.OnChanged("Item2")
        End Set
    End Property
    Public Property Item3 As ClassItem
        Get
            Return Me.mItem3
        End Get
        Set(ByVal value As ClassItem)
            Me.mItem3 = value
            Me.OnChanged("Item3")
        End Set
    End Property

    Public Sub OnChanged(ByVal info As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
    End Sub
End Class
Public Class ClassItem
    Implements INotifyPropertyChanged
    Public Event PropertyChanged(ByVal sender As Object, ByVal e As System.ComponentModel.PropertyChangedEventArgs) Implements System.ComponentModel.INotifyPropertyChanged.PropertyChanged
    Private mValue1 As Integer = 0
    Private mValue2 As Integer = 0
    Private mValue3 As Integer = 0
    Public Property Value1 As Integer
        Get
            Return Me.mValue1
        End Get
        Set(ByVal value As Integer)
            Me.mValue1 = value
            Me.OnChanged("Value1")
        End Set
    End Property
    Public Property Value2 As Integer
        Get
            Return Me.mValue2
        End Get
        Set(ByVal value As Integer)
            Me.mValue2 = value
            Me.OnChanged("Value2")
        End Set
    End Property
    Public Property Value3 As Integer
        Get
            Return Me.mValue3
        End Get
        Set(ByVal value As Integer)
            Me.mValue3 = value
            Me.OnChanged("Value3")
        End Set
    End Property
    Public Sub OnChanged(ByVal info As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
    End Sub
End Class
End Class

    <Style x:Key="MyExpander" TargetType="Expander" >
        <Setter Property="Header" Value="{Binding Name}"/>
        <Setter Property="Margin" Value="1"/>
        <Setter Property="BorderBrush" Value="{StaticResource BrushBorderNormal}"/>
        <Setter Property="Background" Value="{StaticResource BrushBackNormal}"/>
        <!--<Setter Property="IsExpanded" Value="{Binding Expander}"/>-->
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="Expander">
                    <Grid>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto"/>
                            <RowDefinition Height="*" />
                            <RowDefinition Height="Auto"/>
                        </Grid.RowDefinitions>
                        <Border Name="Border" Grid.RowSpan="3" BorderThickness="1" CornerRadius="3" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" />
                        <ToggleButton Name="Toggle" IsChecked="{Binding Path=IsExpanded,Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" 
                                      BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}"  
                                      Content="{TemplateBinding Header}" FontWeight="Bold" Style="{DynamicResource StyleCheckExpander}" Foreground="Blue" />
                        <ToggleButton IsChecked="{Binding Access}" Width="20" Margin="2" HorizontalAlignment="Right" Style="{DynamicResource StyleCheckAccess}"/>
                        <Grid Grid.Row="1" Margin="5,3,3,3" Name="Detail" >
                            <ContentControl Content="{TemplateBinding Content}" x:Name="ExpanderContent" Visibility="Visible"/>
                        </Grid>
                        <TextBlock Name="Text" FontSize="10" Foreground="Blue" FontWeight="Bold" Visibility="Collapsed" Grid.Row="2" Margin="2" Text="{Binding Text}" TextWrapping="WrapWithOverflow">
                            <TextBlock.Effect>
                                <DropShadowEffect BlurRadius="1" ShadowDepth="1" Color="Silver" />                                             
                            </TextBlock.Effect>
                        </TextBlock>
                        <!--<Border Grid.RowSpan="2" Style="{StaticResource BorderLighTop}"/>-->
                        <!--<Border Grid.RowSpan="2" Style="{StaticResource BorderDarkBottom}"/>-->
                    </Grid>
                    <ControlTemplate.Triggers>
                        <DataTrigger Binding="{Binding Access}" Value="False">
                            <Setter TargetName="Text" Property="Foreground" Value="Black" />
                            <Setter Property="BorderBrush" Value="#FF313131" />
                            <Setter Property="Background" Value="WhiteSmoke" />
                            <Setter TargetName="Toggle" Property="Foreground" Value="Black" />
                        </DataTrigger>
                        <Trigger Property="IsExpanded" Value="False">
                            <Setter TargetName="Detail" Property="Visibility" Value="Collapsed" />
                            <Setter TargetName="Text" Property="Visibility" Value="Visible" />
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="False">
                            <!--<Setter Property="IsExpanded" Value="False" />-->
                            <!--<Setter TargetName="ExpanderButton" Property="Background" Value="{StaticResource DisabledBackgroundBrush}" />-->
                            <!--<Setter TargetName="ExpanderButton" Property="Background" Value="{StaticResource DisabledBackgroundBrush}" />-->
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style> <!--MyExpander-->

Me.DataContext = Me.CF

<Grid DataContext="{StaticResource CF}">