Thank you for writing back.
To make sure we are on the same page, I would like to restate the answer from my previous post. You are able to achieve the desired layout using one RadPageView in ExplorerBar mode and a nested RadPageView in Stack mode for groups. The controls you mentioned that you will use, adopt a similar approach for creating such scenario - each group is a separate control that should be added manually to the bar.
Regarding the image in our website, we will take your opinion under consideration. It will be replaced with an image demonstrating a clearer scenario. Thank you for your feedback.
Feel free to write back if you encounter further issues.
the Telerik team