<!-- BinaryTreeNodeView.xaml -->
<UserControl x:Class="BinaryTreeControl.Views.BinaryTreeNodeView"
             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"
             xmlns:local="clr-namespace:BinaryTreeControl.Views"
             mc:Ignorable="d">
    <StackPanel>

        <TextBlock Text="Node" TextAlignment="Center"/>

        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition/>
                <ColumnDefinition/>
            </Grid.ColumnDefinitions>

            <ContentControl Grid.Column="0" Content="{Binding Left, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=local:BinaryTreeNodeView}}"/>

            <ContentControl Grid.Column="1" Content="{Binding Right, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=local:BinaryTreeNodeView}}"/>
        </Grid>
    </StackPanel>
</UserControl>



// BinaryTreeNodeView.cs
using System.Windows.Controls;

namespace BinaryTreeControl.Views
{
    /// <summary>
    /// Логика взаимодействия для BinaryTreeNodeView.xaml
    /// </summary>
    public partial class BinaryTreeNodeView : UserControl
    {
        public BinaryTreeNodeView()
        {
            Left = new BinaryTreeNodeView(new BinaryTreeNodeView(null, null), new BinaryTreeNodeView(null, null));
            Right = new BinaryTreeNodeView(new BinaryTreeNodeView(null, null), new BinaryTreeNodeView(null, null));

            InitializeComponent();
        }

        public BinaryTreeNodeView(BinaryTreeNodeView left, BinaryTreeNodeView right)
        {
            Left = left;
            Right = right;

            InitializeComponent();
        }

        public BinaryTreeNodeView Left { get; set; }

        public BinaryTreeNodeView Right { get; set; }
    }
}



<!-- MainWindow.xaml -->
<Window x:Class="BinaryTreeControl.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:BinaryTreeControl.Views"
        mc:Ignorable="d"
        Width="300"
        Height="300"
        Title="MainWindow">
    <Grid>
        <local:BinaryTreeNodeView/>
    </Grid>
</Window>