There is not an option to delete permanently the endpoint tree levels which are not of interest to you. However, a new filter option for customizing data matrix is available in TB v.4.2. The filter allows you to remove all information which is not needed at the current moment (i.e. filtering is for the current document, only).
In order to customize your data matrix, you should click the Manual filtering icon (1) (Figure 1). Window with the endpoint tree organization appears and you can select only the nodes which you want to see. Once the nodes are selected just confirm by OK (2)