data source multiple collections

Hi 

I need to source data had several collections 

I used CompositeCollection 

<DataGrid.Resources>
                <CollectionViewSource x:Key="CollectionSourceOne" Source="{Binding Path=ObservableCollectionSearch}"/>
                <CollectionViewSource x:Key="CollectionSourceTwo" Source="{Binding Path=ObservableCollectionNomenclatureServK}"/>
            </DataGrid.Resources>
            <DataGrid.ItemsSource>
                <CompositeCollection>

   <CollectionContainer Collection="{Binding Source={StaticResource CollectionSourceOne}}"/>                      <CollectionContainer Collection="{Binding Source={StaticResource CollectionSourceTwo}}"/>
                 
                </CompositeCollection>
            </DataGrid.ItemsSource>

I have two datagrid columns 

  <DataGrid.Columns>

                <DataGridTextColumn Header="Name Service" Width="*" Binding="{Binding  NameServ, Mode=OneWay}" Visibility="Visible">
                    <DataGridTextColumn.HeaderStyle>
                        <Style TargetType="DataGridColumnHeader">
                            <Setter Property="HorizontalContentAlignment" Value="Center"/>
                            <Setter Property="VerticalContentAlignment" Value="Center"/>
                        </Style>
                    </DataGridTextColumn.HeaderStyle>
                </DataGridTextColumn>


                <DataGridTextColumn Header="Type service" Width="*" Binding="{Binding TypeServ, Mode=OneWay}" Visibility="Visible">
                    <DataGridTextColumn.HeaderStyle>
                        <Style TargetType="DataGridColumnHeader">
                            <Setter Property="HorizontalContentAlignment" Value="Center"/>
                        </Style>
                    </DataGridTextColumn.HeaderStyle>
                </DataGridTextColumn>

NameServ property CollectionSourceOne, TypeServ property CollectionTwo 

But binding occurs only with the first collection, Why?