public partial class Customer
{
    public Customer()
    {
        this.Consignee = new HashSet<Consignee>();
    }

    public int idCustomer { get; set; }
    public string nameCustomer { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Consignee> Consignee { get; set; }
}

public partial class Consignee
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Consignee()
    {
        this.Servers = new HashSet<Servers>();
        this.Systems = new HashSet<Systems>();
    }

    public int idConsignee { get; set; }
    public int idCustomerConsignee { get; set; }
    public string nameConsignee { get; set; }

    public virtual Customer Customer { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Servers> Servers { get; set; }
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<Systems> Systems { get; set; }
}

public partial class Servers
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public Servers()
    {
        this.Licence = new HashSet<Licence>();
    }

    public string idUidServer { get; set; }
    public string ipServer { get; set; }
    public Nullable<int> idConsigneeServer { get; set; }

    public virtual Consignee Consignee { get; set; }
}

<TreeView x:Name="tvForLic">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Path = Consignee}" >
                <TextBlock Text="{Binding Path= nameCustomer}" />
                <HierarchicalDataTemplate.ItemTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding Path= nameConsignee}" />
                    </DataTemplate>
                </HierarchicalDataTemplate.ItemTemplate>
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>

<TreeView x:Name="tvForSystem" ItemsSource="{Binding Consignee}">
        <TreeView.Resources>
            <HierarchicalDataTemplate DataType="{x:Type local:Systems}" ItemsSource="{Binding Consignee}">
            <StackPanel Orientation="Horizontal">
                <CheckBox Margin="2" />
                <TextBlock Text="{Binding nameSystem}" />
            </StackPanel>
            </HierarchicalDataTemplate>
            <HierarchicalDataTemplate DataType="{x:Type local:Customer}" ItemsSource="{Binding Consignee}">
                <StackPanel Orientation="Horizontal">
                    <CheckBox Margin="2" />
                    <TextBlock Text="{Binding nameCustomer}" />
                </StackPanel>
            </HierarchicalDataTemplate>
        </TreeView.Resources>
    </TreeView>

xmlns:local="clr-namespace:LicenseManager"

<TreeView x:Name="tvForSystem" ItemsSource="{Binding Consignee}">
        <TreeView.Resources>
            <HierarchicalDataTemplate DataType="{x:Type local:Customer}" ItemsSource="{Binding Consignee}" >
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="{Binding nameCustomer}" />
            </StackPanel>
            </HierarchicalDataTemplate>
            <HierarchicalDataTemplate DataType="{x:Type local:Consignee}" ItemsSource="{Binding Consignee}">
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="{Binding nameConsignee}" />
                </StackPanel>
            </HierarchicalDataTemplate>
            <DataTemplate DataType="{x:Type local:Systems}">
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="{Binding nameConsignee}" />
                </StackPanel>
            </DataTemplate>
        </TreeView.Resources>