I have this class:

public class Team
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ObservableCollection<Competency> Competencies { get; set; } = new ObservableCollection<Competency>();

    public ObservableCollection<Employee> Employees { get; set; } = new ObservableCollection<Employee>();
}

And this code works for me:

<Page>
    <Page.Resources>
        <model:Employee x:Key="employees" />
        <HierarchicalDataTemplate DataType="{x:Type model:Team}" ItemsSource="{Binding Employees}">
            <StackPanel Orientation="Horizontal">
                <TextBlock Text="{Binding Row.Name}" FontWeight="Bold" Margin="3,0,0,0" />
            </StackPanel>
        </HierarchicalDataTemplate>
        
        <DataTemplate DataType="{x:Type model:Employee}">
            <StackPanel Orientation="Vertical">
                <Border Padding="2" HorizontalAlignment="Stretch" VerticalAlignment="Center" BorderBrush="#FFC3CEDC" BorderThickness="0,1,0,0">
                    <Grid HorizontalAlignment="Stretch" VerticalAlignment="Center">
                        <Grid.RowDefinitions>
                            <RowDefinition />
                            <RowDefinition />
                        </Grid.RowDefinitions>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="130" />
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="*" />
                            <ColumnDefinition Width="*" />
                        </Grid.ColumnDefinitions>
                        <StackPanel Orientation="Horizontal" Grid.Column="0">
                            <TextBlock Text="{Binding Row.FirstName}" FontWeight="Bold" Margin="3,0,0,0" />
                            <TextBlock Text="{Binding Row.LastName}" Margin="3,0,0,0" />
                        </StackPanel>
                    </Grid>
                </Border>
            </StackPanel>
        </DataTemplate>
    </Page.Resources>

    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>

        <!-- TreeListControl for Teams -->
        <dxg:TreeListControl x:Name="teamEmployeesTree" Grid.Column="0" ItemsSource="{Binding TeamsItems}">
            <dxg:TreeListControl.View>
                <dxg:TreeListView 
                     TreeDerivationMode="HierarchicalDataTemplate" 
                     AutoExpandAllNodes="True" 
                     ShowCheckboxes="True" 
                     AllowRecursiveNodeChecking="False"
                     NewItemRowPosition="Top" 
                     AllowPerPixelScrolling="True"
                     TreeColumnFieldName="Name"
                     NavigationStyle="Cell"
                     AllowDragDrop="True"
                     ShowDragDropHint="False"
                     ShowNodeImages="True"
                     UseEvenRowBackground="True"
                     EnterMoveNextColumn="False"/>
            </dxg:TreeListControl.View>
            <dxg:TreeListColumn FieldName="Name" />
            <dxg:TreeListColumn FieldName="Competencies"/>
        </dxg:TreeListControl>
    </Grid>
</Page>

Now what I want is to have another type of child node, so I need some kind group by thing here:

Team (root)
 - "Employees" (fixed node text, and when I click on this to present all employees for that team)
   --Emp1
   --Emp2
 - "Competencies" - (fixed node text, and when I click on this to present all employees for that team)
   -- Competency1
   -- Competency2

Also I need checkbox “Is TeamLead” but only for employees.

Is this possible and to have different columns inside each nodes group?