C# ObjectListView TreeListView add multi-level Nodes

I’m using ObjectListView.Official.2.9.1.nupkg
http://objectlistview.sourceforge.net/cs/index.html

How i can add third level grandchild into TreeListView (inside "CHILD_1_1" and make it expandable)?

public partial class DocumentLink : Form
{
    // embedded class
    class Node
    {
        public string Name { get; private set; }
        public string Column1 { get; private set; }
        public string Column2 { get; private set; }
        public string Column3 { get; private set; }
        public List<Node> Children { get; private set; }
        public Node(string name, string col1, string col2, string col3)
        {
            this.Name = name;
            this.Column1 = col1;
            this.Column2 = col2;
            this.Column3 = col3;
            this.Children = new List<Node>();
        }
    }

    // private fields
    private List<Node> data;
    private BrightIdeasSoftware.TreeListView treeListView;

    public DocumentLink()
    {
        InitializeComponent();
        AddTree();
        InitializeData();
        FillTree();
    }

    // private methods
    private void FillTree()
    {
        // set the delegate that the tree uses to know if a node is expandable
        this.treeListView.CanExpandGetter = x => (x as Node).Children.Count > 0;
        // set the delegate that the tree uses to know the children of a node
        this.treeListView.ChildrenGetter = x => (x as Node).Children;

        // create the tree columns and set the delegates to print the desired object proerty
        var nameCol = new BrightIdeasSoftware.OLVColumn("Name", "Name");
        nameCol.AspectGetter = x => (x as Node).Name;

        var col1 = new BrightIdeasSoftware.OLVColumn("Column1", "Column1");
        col1.AspectGetter = x => (x as Node).Column1;

        var col2 = new BrightIdeasSoftware.OLVColumn("Column2", "Column2");
        col2.AspectGetter = x => (x as Node).Column2;

        var col3 = new BrightIdeasSoftware.OLVColumn("Column3", "Column3");
        col3.AspectGetter = x => (x as Node).Column3;

        // add the columns to the tree
        this.treeListView.Columns.Add(nameCol);
        this.treeListView.Columns.Add(col1);
        this.treeListView.Columns.Add(col2);
        this.treeListView.Columns.Add(col3);

        // set the tree roots
        this.treeListView.Roots = data;
    }

    private void InitializeData()
    {
        // create fake nodes
        var parent1 = new Node("PARENT1", "-", "-", "-");
        parent1.Children.Add(new Node("CHILD_1_1", "A", "X", "1"));
        parent1.Children.Add(new Node("CHILD_1_2", "A", "Y", "2"));
        parent1.Children.Add(new Node("CHILD_1_3", "A", "Z", "3"));

        var parent2 = new Node("PARENT2", "-", "-", "-");
        parent2.Children.Add(new Node("CHILD_2_1", "B", "W", "7"));
        parent2.Children.Add(new Node("CHILD_2_2", "B", "Z", "8"));
        parent2.Children.Add(new Node("CHILD_2_3", "B", "J", "9"));

        var parent3 = new Node("PARENT3", "-", "-", "-");
        parent3.Children.Add(new Node("CHILD_3_1", "C", "R", "10"));
        parent3.Children.Add(new Node("CHILD_3_2", "C", "T", "12"));
        parent3.Children.Add(new Node("CHILD_3_3", "C", "H", "14"));

        data = new List<Node> { parent1, parent2, parent3 };
    }

    private void AddTree()
    {
        treeListView = new BrightIdeasSoftware.TreeListView();
        treeListView.Dock = DockStyle.Fill;
        this.Controls.Add(treeListView);
    }
}

Now i only able to add second level as shown.

Other using this Nuget package, can i do this with only using System.Windows.Forms.ListView?
*A TreeView list with columns.

>Solution :

You should be able to do this in the same way that you added the first child to the first parent.
Create the instance of the node, then add it to the parent, and add other nodes to it… Should be something like this:

private void InitializeData()
{
    // create fake nodes
    var parent1 = new Node("PARENT1", "-", "-", "-");
    var child1 = new Node("CHILD_1_1", "A", "X", "1");
    parent1.Children.Add(child1);
    var childChild1 = new Node("CHILD_1_1_CHILD", "T", "R", "45");
    child1.Children.Add(childChild1);
    parent1.Children.Add(new Node("CHILD_1_2", "A", "Y", "2"));
    parent1.Children.Add(new Node("CHILD_1_3", "A", "Z", "3"));

    var parent2 = new Node("PARENT2", "-", "-", "-");
    parent2.Children.Add(new Node("CHILD_2_1", "B", "W", "7"));
    parent2.Children.Add(new Node("CHILD_2_2", "B", "Z", "8"));
    parent2.Children.Add(new Node("CHILD_2_3", "B", "J", "9"));

    var parent3 = new Node("PARENT3", "-", "-", "-");
    parent3.Children.Add(new Node("CHILD_3_1", "C", "R", "10"));
    parent3.Children.Add(new Node("CHILD_3_2", "C", "T", "12"));
    parent3.Children.Add(new Node("CHILD_3_3", "C", "H", "14"));

    data = new List<Node> { parent1, parent2, parent3 };
}