Another mechanism that might work here, and likely doesn't really require changes to the data model, would be to allow the list to be collapsed by 'save to' path.
I've got rules set up so things download to (basically) a path like
e:\jdownload\$host\$poster\$packagegroup\$package
all based of regex field extraction. For instance
e:\jdownload\youtube\MasqueradeJacker\Dark Fantasy GMVs\ (packages)
e:\jdownload\youtube\MasqueradeJacker\Hybrid GMVs\ (packages)
e:\jdownload\youtube\MasqueradeJacker\Light Fantasy\GMVs\ (packages)
Being able to collapse the list by directory could let me, for example:
- roll everything up by host
- roll everything up by host and poster
- roll everything up by host, poster, and package group.
This is probably 'just' an interface change, needing to introduce a new type of grouping to the data model.