Create Palette with GroupNode where GroupNode contain multiple ControlNodes.

   //initializing the label control
            System.Windows.Forms.Label label = new System.Windows.Forms.Label();
            label.Size = new System.Drawing.Size(200, 25);
            label.Text = "Label";
            label.Name ="Label";
            label.TextAlign = ContentAlignment.MiddleCenter;
 
            //initializing the textbox control
            TextBox textbox = new TextBox();
            textbox.MinimumSize = new System.Drawing.Size(200, 400);
            textbox.Text = "TextBox";
            textbox.Name = "TextBox";
 
            //adding a textbox to diagram's control node
            ControlNode textboxCtrlNode = new ControlNode(textbox, new RectangleF(0, 0, 200, 100));
            textboxCtrlNode.Name = "TextBoxControl";
            textboxCtrlNode.ActivateStyle = ActivateStyle.ClickPassThrough;
 
            //adding a label to diagram's control node
            ControlNode labelCtrlNode = new ControlNode(label, new RectangleF(0, 100, 200, 25));
            labelCtrlNode.ActivateStyle = ActivateStyle.ClickPassThrough;
            labelCtrlNode.Name = "LabelControl";
 
            Group group = new Group();
            group.Name = "GroupNode";
 
            //adding symbols to group node
            group.AppendChild(textboxCtrlNode);
            group.AppendChild(labelCtrlNode);
 
            diagram1.Model.AppendChild(group);
            
            //adding symbols to palette
            SymbolPalette symbol = new SymbolPalette();
            symbol.AppendChild(group);
 
            paletteGroupBar1.AddPalette(symbol);
 

   'initializing the label control
   Dim label As New System.Windows.Forms.Label()
   label.Size = New System.Drawing.Size(200, 25)
   label.Text = "Label"
   label.Name ="Label"
   label.TextAlign = ContentAlignment.MiddleCenter
 
   'initializing the textbox control
   Dim textbox As New TextBox()
   textbox.MinimumSize = New System.Drawing.Size(200, 400)
   textbox.Text = "TextBox"
   textbox.Name = "TextBox"
 
   'adding a textbox to diagram's control node
   Dim textboxCtrlNode As New ControlNode(textbox, New RectangleF(0, 0, 200, 100))
   textboxCtrlNode.Name = "TextBoxControl"
   textboxCtrlNode.ActivateStyle = ActivateStyle.ClickPassThrough
 
   'adding a label to diagram's control node
   Dim labelCtrlNode As New ControlNode(label, New RectangleF(0, 100, 200, 25))
   labelCtrlNode.ActivateStyle = ActivateStyle.ClickPassThrough
   labelCtrlNode.Name = "LabelControl"
 
   Dim group As New Group()
   group.Name = "GroupNode"
 
   'adding symbols to group node
   group.AppendChild(textboxCtrlNode)
   group.AppendChild(labelCtrlNode)
 
   diagram1.Model.AppendChild(group)
 
   'adding symbols to palette
   Dim symbol As New SymbolPalette()
   symbol.AppendChild(group)
 
   paletteGroupBar1.AddPalette(symbol)