Relf-reference using OA

[Ubuntu]

Dear All,
I have the following implementation for treeview using EF4, I tried to do the same using OA but with no luck, here we go:
On EF4 dmx diagram I have the following setting for my group table:
Parent: 0..1 (Zero or One)
Children: * (Many)
which are define as association on the group table.

I then have this xaml for the itemtemplate

    <telerik:HierarchicalDataTemplate x:Name="ItemTemplate" ItemsSource="{Binding Children}">
    <Grid>
        <Grid.ColumnDefinitions>
        <ColumnDefinition Width="16"/>
        <ColumnDefinition Width="Auto"/>
        </Grid.ColumnDefinitions>
        <TextBlock x:Name="Label" Text="{Binding groupname}" Grid.Column="1"/>
    </Grid>
</telerik:HierarchicalDataTemplate>

Also this is the treeview xaml showing the binding to the groupcollection

<telerik:RadTreeView x:Name="Treeofgroups" FontSize="11" Grid.Row="1"
    IsLineEnabled ="True"
    ItemTemplate="{StaticResource ItemTemplate}"
    IsLoadOnDemandEnabled="True"
    LoadOnDemand="ItemExpanded"
    SelectedItem="{Binding CurrentSelected,Mode=TwoWay}"
    ItemsSource="{Binding GroupCollection,Mode=TwoWay}"
</telerik:RadTreeView>

In my ViewModel I have a QueryableDomainServiceCollectionView<group> GroupCollection to hold the list of groups from the domainservice using the following method on the domainservice:

public IQueryable<group> Getgroups()
{
    return this.ObjectContext.group.Include("Children").Where(p => p.parentid == null || p.parentid == "");
}

I also have this method to get the subgroups when the treeview get expanded (loaded Ondemand);

public IQueryable<group> GetChildrenByParentID(string parentID)
{
    return this.ObjectContext.group.Include("Children").Where(p => p.parentid == parentID);
}

I can't do the same implementation on the OA domainservice.

How can I achieve this scenario in treeview & OA.

Best regards

[Ubuntu]

Dear All,

Never mind, I mange to get it to work.
I just removed the .Include("Children") and everything else is just fine.

Best