The new "tabbed" interface of GoldMine Premium makes for a much "cleaner" workspace, however; it sometimes makes users forget that they can look at more than one record at once.
To do this, simply select Window | New Contact Window. (Older versions of GoldMine will have this under View | New Contact Window)
This will bring up a new "Contact Search" tab. Simply search for the contact you wish to view. You'll now have two separate tabs, each looking at a different contact record.