<Window x:Class="LayoutPanels.DoubleSplitWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="DoubleSplitWindow" Height="300" Width="300"
    >
    <Grid>      
      <Grid.ColumnDefinitions>
        <ColumnDefinition></ColumnDefinition>
        <ColumnDefinition Width="Auto"></ColumnDefinition>
        <ColumnDefinition></ColumnDefinition>
      </Grid.ColumnDefinitions>

      <Grid Grid.Column="0" VerticalAlignment="Stretch">
        <Grid.RowDefinitions>
          <RowDefinition></RowDefinition>          
          <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Button Margin="3" Grid.Row="0">Top Left</Button>
        <Button Margin="3" Grid.Row="1">Bottom Left</Button>
      </Grid>

      <GridSplitter Grid.Column="1" 
                  Width="3" VerticalAlignment="Stretch" HorizontalAlignment="Center" 
                  ShowsPreview="False"></GridSplitter>

      <Grid Grid.Column="2">
        <Grid.RowDefinitions>
          <RowDefinition></RowDefinition>
          <RowDefinition Height="Auto"></RowDefinition>
          <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>

        <Button Grid.Row="0" Margin="3">Top Right</Button>
        <Button Grid.Row="2" Margin="3">Bottom Right</Button>
        
         <GridSplitter Grid.Row="1" 
                  Height="3" VerticalAlignment="Center" 
                  HorizontalAlignment="Stretch" 
                  ShowsPreview="False"></GridSplitter>
      </Grid>

      
      
    </Grid>
</Window>
