Is it possible to get a Meny Property here? It would be nice to be able to
connect a PopupMenu to the button.


Thank you for your suggestion.
We will consider adding functionality to open a PopupMenu from the TIWAdvToolButton in a future version of the TMS IntraWeb Component Pack.

As an alternative, have you tried using the TIWAdvSelector control?
This control has the ability to display a fully configurable dropdown menu when clicked, that can be used as a menu selector.

Examples can be found in the TMS IW Features Demo application.