Hi Jeena,
Thank you for evaluating Syncfusion Products.
You can add TreeView within GroupBar dynamically by using the below code:
'Add treeview to GroupBarTemplateControl
Dim template As GroupBarTemplateControl = New GroupBarTemplateControl()
template.ID = "templateId"
template.Controls.Add(treeview)
Me.Groupbar2.Templates.Add(template)
'Add GroupBarTemplateControl to GroupBarItem
Dim networkPlace As GroupBarItem = New GroupBarItem()
networkPlace.TemplateID = "templateId"
networkTasks.Items.Add(networkPlace)
Me.Groupbar2.Items.Add(networkTasks)
Please refer the sample in the below link which illustrates the above:
http://websamples.syncfusion.com/samples/Tools.Web/6.2.0.40/Tools_Asp_GroupbarItem_46877/main.htmPlease try this and let me know if this helps.
Thanks,
Melba