I'd like to add a simple TextBlock aligned to the right of the group panel. I feel like this is a modify the control template task, but I don't know how to begin.
This can be achieved by modifying the ControlTemplate for GridViewGroupPanelTemplate. You can learn more about that in the Editing Control Templates article.
Attached, you can find a sample project in which I've extracted the ControlTemplate and added a TextBlock on the right side of the GroupPanel.
Please, let me know if that answers your query.
Regards,
Dimitar Dinev
Progress Telerik
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