OK, So, as there's more than one it's still not 100% clear to me what you need precisely, but, I reckon I can get you started...
Let's say, for the sake of argument, that you move (via drag and drop is easiest) all the relevant playlists from "Imported" to a new group called m3u. Amend the smartlist rule to fit with whatever you do with them.
p=m3u [Last Played]=>2w ~sort=Random
Hint: Use the "Import/Export" button to paste the code above into the smartlist rule editor, and amend as required before hitting the OK button.
- p=m3u: This restricts the list to just the files that are included in any of the playlists in the "m3u" group
- [Last Played]=>2w: This excludes anything played in the past 2 weeks
- ~sort=Random: This shuffles the results
If you wanted to further restrict the source set of files, you might use, for example p="m3u\Dennis Coffey" to limit the the initial set of files to just those on the Dennis Coffey playlist. Note that if there is a space involved, wrap it in quotes.
Does that help?