Yes, I have recently encountered the same issue.
I will report this to Graphisoft HQ.
Thank you, Laszlo.
This is more of a problem for Mac users of PARAM-O, as PC users can download the previous version of PARAM-O and see a proper list there, but Mac users can not, as this is the first release of PARAM-O for Mac and Global Variables are unusable.
However, this is the list of how it should look like and a simple work-around for Mac crowd for now is to take a look at the image attached to this message and simply count the rows down to a particular global viable... the list in the Mac version is the same as in PC version and the Global Variables actually work as they should... it is just a selection list that is broken...