I want to use win explorer bar with more then 2 leves of hirarchy.
Inside each group, I want to be able to add a UltraTree, and not just an item.
For example, in the samples we got the main navigation screen, is built like this.
Set the UltraExplorerBar.GroupSettings.Style property to ControlContainer. This causes a Panel-derived control to be positioned within the group's item area, on which you can site any control(s) you like, including UltraTree.