Thank you for the response, though I have already looked at these materials.
iTunes only saves the .xml folder in an upper level “music” folder ([server]://music); where the music media is in [server]//music/iTunes/iTunes Media/music
From that default location Roon recognizes enough to download ~ 1/2 of the playlist names, and a small amount of the tracks of those playlists.
The support page suggests that the .xml file will be placed in the iTunes folder; (as noted in the attached screenshot) though that is not the case on any of my Macs (all of which put the .xml file in the “music” folder, which also contains the itunes/iTunes Media folders).
Nevertheless, I have tried placing the .xml folder in the iTunes folder and rescanning; and then in the iTunes Media folder and rescanning. In both cases, the result was no playlists being found. So as a result, I placed the .xml file back in the default "music” folder (containing iTunes/iTunes Media/music).
All of my music files are in the folder: iTunes/iTunes Media/music Similarly the .xml (now back in the same upper level “music” folder as “iTunes is being updated.