How to paint implementations in UML?

Hello,

currently I'm documenting some code, so I need the class hierarchy. It's easily working to show the parent classes for a certain class. But how can I go the other direction to get a complete class hierarchy diagramm? I have the option "show implementations" (Ctrl-Alt-B I guess) that shows a list of classes that are inheriting. Is there any way to get this list into the hierarchy diagram?