<hdc:DataTreeGrid>
    <hdc:DataTreeGrid.Columns>
        <hdc:DataTreeGridColumn Header="Node"/>
        <d:DataGridTextColumn Header="Indentation" Binding="{Binding Indentation}" IsReadOnly="True"/>
        <d:DataGridCheckBoxColumn Header="IsExpanded" Binding="{Binding IsExpanded}" IsReadOnly="True"/>
    </hdc:DataTreeGrid.Columns>
    <hdc:DataTreeGrid.Items>
        <hdc:DataTreeGridItem Content="Node 1"/>
        <hdc:DataTreeGridItem Content="Node 1.1" Indentation="1"/>
        <hdc:DataTreeGridItem Content="Node 1.2" Indentation="1"/>
        <hdc:DataTreeGridItem Content="Node 2"/>
        <hdc:DataTreeGridItem Content="Node 2.1" Indentation="1"/>
        <hdc:DataTreeGridItem Content="Node 2.2" Indentation="1"/>
        <hdc:DataTreeGridItem Content="Node 2.2.1" Indentation="2"/>
        <hdc:DataTreeGridItem Content="Node 2.2.2" Indentation="2"/>
    </hdc:DataTreeGrid.Items>
</hdc:DataTreeGrid>