Sorry, but we cannot understand the problem. Could you please explain it in more details?
Categories Tree control work in this way:
By default Categories Tree control display all categories with sub categories. If you want to set a filter for categories, expand section Filters, and set a category for which you want to filter the tree view in the field RootCategory.
If you want to set the root category to be shown in the tree view, expand section Behavior, and select True for ShowRootCategory.
The values in the MaxDataBindDepth field allows you to set the maximum number of hierarchical levels to be displayed. The default is -1, which binds all the levels in the data source to the control.
the Telerik team