Actually a portal CAN show records from the same table as the layout. It just takes a "self join" relationship created in Manage | Database | Relationships.
Go to that location, click on the "box" for this layout's table to select it, then click the button with two green plus signs. This creates a new "table occurrence" of the same table and you can double click it to open a dialog where you can give it a more descriptive name than just putting a 2 after the original occurrence's name.
Then you can treat this like any other table occurrence to create a relationship between the two and now you can put a portal to this new table occurrence on the layout shown above.
The relationship would look something like this:
PMR::FK_Project_ID = PMR 2::FK_Project_ID
if you want to see all PMR records for the same project in your portal.
If "table occurrence" is a new concept, you might want to read this thread: Tutorial: What are Table Occurrences?
That did the trick. Thanks so much Phil. As always, your help is appreciated.
I have heard the term thrown around, but haven't fully wrapped my head around the concept. The linked post is very informative. It's starting to make sense why that functinality is available.