You can download example code here:
In the code you actually use a Dictionary. The Key is the name and the Value what is returned. It is possible to return an object instead of a name, but it might be very difficult to do so. At least the bast way is to fill the Dictionary with the name and the Object Handle, which can be converted to an object.
The node always returns one object, it is not possible to return multiple objects from a drop down. Maybe you can have a look at certain packages which are able to show listbox with multi-selection dialogs.