Events in MultiTextNode children

I just GoDiagram.Net win for evaluation. In the demo1 sample, how do go about capturing and event such as double-click on the text nodes or images under the GoMultiTextNode example implemented in the RecordNode class?

Well, the most obvious way is to define a GoView.ObjectDoubleClicked event handler. Look at the object that was clicked, and determine what kind of object it is and its relationship to the object that you want to deal with. Usually this involves looking at the parent object, but perhaps not in your case.
Alternatively, alter the RecordItem class to override DoDoubleClick.