Popovers are a great new feature in FileMaker Pro 13. They can contain a variety of different layout objects, including portals. However, when the popover object is in a portal, it will not display a secondary portal. This is because a portal cannot contain a portal, or more accurately, a portal will only display a subordinate portal in the first row.
There are a couple of work arounds. Go tohttp://newleafdata.com/downloads-fmp…. to download a free file to see a couple approaches.