MainWindow.xaml:
================


<Window x:Class="InfraWPFDock.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:igDock="http://infragistics.com/DockManager"
        xmlns:local="clr-namespace:InfraWPFDock"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
            <DataTemplate x:Key="viewTemplate">
                <local:UserControl1/>
            </DataTemplate>
        <local:PaneDataTemplateSelector ViewTemplate="{StaticResource viewTemplate}" 
                                        x:Key="paneDataTemplateSelector" />
    </Window.Resources>
    <Grid>
        <igDock:XamDockManager>
            <igDock:DocumentContentHost>

                <igDock:SplitPane>

                    <igDock:TabGroupPane Name="tab1" ItemsSource="{Binding MyFriends}"
         ContentTemplateSelector="{StaticResource paneDataTemplateSelector}">
                       
                    </igDock:TabGroupPane>
                    </igDock:SplitPane>
                </igDock:DocumentContentHost>

        </igDock:XamDockManager>
    </Grid>
</Window>



MainWindow.xaml.cs:
===================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Infragistics.Windows.DockManager;

namespace InfraWPFDock
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            ContentPane cp1 = new ContentPane();
            cp1.Header = "Content Pane 1";
            ContentPane cp2 = new ContentPane();
            cp2.Header = "Content Pane 2";

            // Add ContentPanes in TabGroupPane Panes collection
            tab1.Items.Add(cp1);
            tab1.Items.Add(cp2);

        }
    }
    public class PaneDataTemplateSelector : DataTemplateSelector
    {
        public DataTemplate ViewTemplate { get; set; } 
        public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            var element = (FrameworkElement)container;
            return ViewTemplate;
        }

    }
}


UserControl1.xaml:
===================

<UserControl x:Class="InfraWPFDock.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             

             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBlock>UserControl1</TextBlock>
    </Grid>
</UserControl>