Hi dnnyobi,

Refer below sample.

Code

C#

DataTable dtSource = null;
private void Form1_Load(object sender, EventArgs e)
{
    dtSource = GetData();
    DataTable dt = GetChildData(-1);
    foreach (DataRow dr in dt.Rows)
    {
        TreeNode parentNode = new TreeNode();
        parentNode.Text = dr["NodeText"].ToString();
        parentNode.Name = dr["NodeID"].ToString();
        AddNodes(ref parentNode);
        treeView1.Nodes.Add(parentNode);
    }
}

private void AddNodes(ref TreeNode node)
{
    DataTable dt = GetChildData(Convert.ToInt32(node.Name));
    foreach (DataRow row in dt.Rows)
    {
        TreeNode childNode = new TreeNode();
        childNode.Name = row["NodeID"].ToString();
        childNode.Text = row["NodeText"].ToString();
        AddNodes(ref childNode);
        node.Nodes.Add(childNode);
    }
}

public DataTable GetChildData(int parentId)
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { new DataColumn("NodeId", typeof(int)), new DataColumn("ParentId", typeof(int)), new DataColumn("NodeText") });
    foreach (DataRow dr in dtSource.Rows)
    {
        if (dr[1].ToString() != parentId.ToString())
        {
            continue;
        }
        DataRow row = dt.NewRow();
        row["NodeId"] = dr["NodeId"];
        row["ParentId"] = dr["ParentId"];
        row["NodeText"] = dr["NodeText"];
        dt.Rows.Add(row);
    }

    return dt;
}

private DataTable GetData()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { new DataColumn("NodeId", typeof(int)), new DataColumn("ParentId", typeof(int)), new DataColumn("NodeText") });
    dt.Rows.Add(0, -1, "Cars");
    dt.Rows.Add(1, -1, "Bikes");
    dt.Rows.Add(2, 1, "Avenger");
    dt.Rows.Add(3, 1, "Unicorn");
    dt.Rows.Add(4, 0, "Alto");
    dt.Rows.Add(5, 0, "Wagon R");
    dt.Rows.Add(6, 4, "Alto LXI");
    dt.Rows.Add(7, 4, "Alto VXI");
    dt.Rows.Add(8, 5, "Wagon R LXI");
    dt.Rows.Add(9, 5, "Wagon R ZXI");
    dt.Rows.Add(10, 6, "Rs.3.75 Lakh");
    dt.Rows.Add(11, 7, "Rs.3.85 Lakh");
    dt.Rows.Add(12, 8, "Rs.4.34 Lakh");
    dt.Rows.Add(13, 9, "Rs.5.44 Lakh");
    dt.Rows.Add(14, 2, "Avenger Cruise");
    dt.Rows.Add(15, 14, "Rs.1.03 Lakh");
    return dt;
}

VB.Net

Private dtSource As DataTable = Nothing
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
    dtSource = GetData()
    Dim dt As DataTable = GetChildData(-1)

    For Each dr As DataRow In dt.Rows
        Dim parentNode As TreeNode = New TreeNode()
        parentNode.Text = dr("NodeText").ToString()
        parentNode.Name = dr("NodeID").ToString()
        AddNodes(parentNode)
        treeView1.Nodes.Add(parentNode)
    Next
End Sub

Private Sub AddNodes(ByRef node As TreeNode)
    Dim dt As DataTable = GetChildData(Convert.ToInt32(node.Name))

    For Each row As DataRow In dt.Rows
        Dim childNode As TreeNode = New TreeNode()
        childNode.Name = row("NodeID").ToString()
        childNode.Text = row("NodeText").ToString()
        AddNodes(childNode)
        node.Nodes.Add(childNode)
    Next
End Sub

Public Function GetChildData(ByVal parentId As Integer) As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("NodeId", GetType(Integer)), New DataColumn("ParentId", GetType(Integer)), New DataColumn("NodeText")})

    For Each dr As DataRow In dtSource.Rows

        If dr(1).ToString() <> parentId.ToString() Then
            Continue For
        End If

        Dim row As DataRow = dt.NewRow()
        row("NodeId") = dr("NodeId")
        row("ParentId") = dr("ParentId")
        row("NodeText") = dr("NodeText")
        dt.Rows.Add(row)
    Next

    Return dt
End Function

Private Function GetData() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.AddRange(New DataColumn() {New DataColumn("NodeId", GetType(Integer)), New DataColumn("ParentId", GetType(Integer)), New DataColumn("NodeText")})
    dt.Rows.Add(0, -1, "Cars")
    dt.Rows.Add(1, -1, "Bikes")
    dt.Rows.Add(2, 1, "Avenger")
    dt.Rows.Add(3, 1, "Unicorn")
    dt.Rows.Add(4, 0, "Alto")
    dt.Rows.Add(5, 0, "Wagon R")
    dt.Rows.Add(6, 4, "Alto LXI")
    dt.Rows.Add(7, 4, "Alto VXI")
    dt.Rows.Add(8, 5, "Wagon R LXI")
    dt.Rows.Add(9, 5, "Wagon R ZXI")
    dt.Rows.Add(10, 6, "Rs.3.75 Lakh")
    dt.Rows.Add(11, 7, "Rs.3.85 Lakh")
    dt.Rows.Add(12, 8, "Rs.4.34 Lakh")
    dt.Rows.Add(13, 9, "Rs.5.44 Lakh")
    dt.Rows.Add(14, 2, "Avenger Cruise")
    dt.Rows.Add(15, 14, "Rs.1.03 Lakh")
    Return dt
End Function

Screenshot