Try naming an object on the popover panel itself (not the button) and Go to that object instead.
Thanks. Tried that--didn't work.
The key is not to put the focus on the button, but the frame.
In layout mode, open the popover.
Select the Popover frame so that it has the selection handles.
Use the Name box in the Inspector to give it an object name.
Now Go to Object, if it specifies the object name of the popover Frame, should open the popover.