But when I reopened the Dimension Pro plug-in window and program browser, I couldn't remember which bank "Accordion 1" was in, so I had no idea where to look for "Accordion 2".
Well, if you haven't loaded more than 8 programs since the "Accordian 1", there's a way to locate the parent folder.
When you open up a fresh instance, click on the right-pointing arrow (just left of the 'Empty Program' text). It will drop down the last eight programs loaded in descending order. Click on '"Accordian 1" to load it into Dimension Pro.
Then go to the Program Handling icon [#1 of four], and select Load Program ... It will point to the subfolder of the last loaded program. Hopefully, it should be easy to spot "Accordian 2.prog" at this point.
Use the same host to get consistent results. In other words, the last 8 programs in the Dimension Pro microhost won't necessarily be the same as the last 8 programs loaded in Sonar. (Rapture has a 16 program history, and seems to hold its listing across multiple hosts.)