Search as you Type example

Hi,

 I was able to do implement search as you type by using this demo as referenced.. 

http://demos.telerik.com/silverlight/#GridView/Search

However, one of my column has listbox control inside.. When im trying to search for an item that exists inside the listbox, no data is being shown, I believe my Search feature is only limited on searching what it can see on the column but not items inside a control in the column.. Is there any way I can implement searching items in my listbox as well?

 I have attached an image of how my application looks like.. Also here is my source code.

   <navigation:Page.Resources>
        <DataTemplate x:Key="CompanyGroupsItemTemplate">
            <Grid>
                <StackPanel Orientation="Horizontal">
                    <Image Source="/AssociationManagementTool;component/Resources/Icons/Bullet.png" Width="5" Height="5" Margin="0,0,4,0" />
                    <TextBlock Text="{Binding GroupName}"  MouseLeftButtonUp="txtGroupName_MouseLeftButtonUp" Cursor="Hand" Width="Auto" />
                </StackPanel>
            </Grid>
        </DataTemplate>
        <DataTemplate x:Key="CompanyGroupList">
            <Grid>
                <ListBox BorderThickness="0" ItemsSource="{Binding CompanyGroups}" ItemTemplate="{StaticResource CompanyGroupsItemTemplate}" ScrollViewer.HorizontalScrollBarVisibility="Disabled" />
            </Grid>
        </DataTemplate>
    </navigation:Page.Resources>



<telerik:RadGridView x:Name="gvCompanyList" MinHeight="343" Margin="0,0,0,5"
                                    IsReadOnly="True" CanUserReorderColumns="True"
                                    EnableRowVirtualization="True" AutoGenerateColumns="False" CanUserFreezeColumns="False" RowIndicatorVisibility="Collapsed" ShowGroupPanel="True" 
                                    SelectionMode="Extended" SelectionUnit="Cell"
       CurrentCellChanged="gvCompanyList_SelectionChanged"
                                    AMT_Utilities:CustomFilterBehavior.TextBox="{Binding ElementName=txtSearchCompany}">
                            <telerik:RadGridView.Columns>
                                <telerik:GridViewDataColumn Header="CompanyID" Width="Auto" DataMemberBinding="{Binding CompanyID}" ShowDistinctFilters="True" IsVisible="False"/>
                                <telerik:GridViewColumn Width="Auto" >
                                    <telerik:GridViewColumn.Header>
                                        <Border Padding="5,0,5,0" BorderThickness="0">
                                            <CheckBox x:Name="chkAllCompany" HorizontalAlignment="Center" VerticalAlignment="Center" Click="chkAllCompany_Click" />
                                        </Border>
                                    </telerik:GridViewColumn.Header>
                                    <telerik:GridViewColumn.CellStyle>
                                        <Style TargetType="telerik:GridViewCell">
                                            <Setter Property="Template">
                                                <Setter.Value>
                                                    <ControlTemplate TargetType="telerik:GridViewCell">
                                                        <Border Padding="5,0,5,0" BorderThickness="0,0,1,1" BorderBrush="#FFB3B3B3">
                                                            <CheckBox x:Name="chkCompany" IsChecked="{Binding IsSelected, Mode=TwoWay}" VerticalAlignment="Center" HorizontalAlignment="Center" Click="chkCompany_Click" />
                                                        </Border>
                                                    </ControlTemplate>
                                                </Setter.Value>
                                            </Setter>
                                        </Style>
                                    </telerik:GridViewColumn.CellStyle>
                                </telerik:GridViewColumn>
                                <telerik:GridViewDataColumn Header="Company" Width="*" DataMemberBinding="{Binding CompanyName}" ShowDistinctFilters="True" />
                                <telerik:GridViewDataColumn Header="Company Type" Width="*" DataMemberBinding="{Binding CompanyType}" ShowDistinctFilters="True" />
                                <telerik:GridViewDataColumn Header="Market" Width="*" DataMemberBinding="{Binding Market}" ShowDistinctFilters="True" />
                                <telerik:GridViewDataColumn Header="Affiliation" Width="*" DataMemberBinding="{Binding Affiliation}" ShowDistinctFilters="True"/>
                                <telerik:GridViewDataColumn Header="Delivery Method" Width="*" DataMemberBinding="{Binding DeliveryMethod}" ShowDistinctFilters="True"/>
                                <telerik:GridViewDataColumn Header="Country/Territory" Width="*" DataMemberBinding="{Binding CountryName}" ShowDistinctFilters="True" />
                                <telerik:GridViewDataColumn UniqueName="colCompanyGroup" Header="Grouped In"  Width="*" CellTemplate="{StaticResource CompanyGroupList}" DataMemberBinding="{Binding CompanyGroupName}" />
                            </telerik:RadGridView.Columns>
                        </telerik:RadGridView>

Please kindly help. Thanks!