<ListBox x:Name="clb_PtGrps" ItemsSource="{Binding PresentationObjects}" >
<ListBox.ItemTemplate>
<HierarchicalDataTemplate>
<CheckBox Content="{Binding Name}" IsChecked="{Binding IsChecked}" HorizontalAlignment="Left"/>
</HierarchicalDataTemplate>
</ListBox.ItemTemplate>
<ListBox.ToolTip>
<ToolTip>
<TextBlock Text="Checked groups will be placed at the top in the same relative order. All others will be sorted."
TextWrapping="WrapWithOverflow" Width="200"/>
</ToolTip>
</ListBox.ToolTip>
</ListBox>