It may take a bit to unpeel all this, especially with all the examples of metadata management we’ve all discussed and the number of times the discussion has been sidetracked.
How about this? Here’s a link to a NEF with XMP sidecar plus PL5 DOP sidecar plus output JPG: Microsoft OneDrive
I set a hierarchical keyword in IMatch for lr:hierarchicalSubject (animals|bird|kestrel|american kestrel). IMatch use this to create a set of flat keywords in dc:subject. The keywords are stored in the XMP sidecar file. You can see the hierarchical keywords via the “1 Default” metadata panel; IMatch hides the dc:subject keywords by default, although you can add that tag to the default panel if you want. The hierarchical keywords were animals|bird|kestrel|american kestrel. The dc:subject contains ‘american kestrel’; ‘animals’; ‘bird’ and ‘kestrel’.
I then used PL 5.1.3 (newest version!) to create a jpg output image. The jpg image hierarchical keywords show up in IMatch as animals|bird|kestrel|american kestrel; animals; bird; kestrel. I.e., ‘animals’, ‘bird’ and ‘kestrel’ have been added to ‘animals|bird|kestrel|american kestrel’. (both NEF and JPG have the same dc:subject contents.
I’ve included ExifTool dumps of both the NEF and JPG files. Note that ExifTool refers to [XMP] Hierarchical Subject for lr:hierarchicalSubject and [XMP] Subject for dc:subject.
(You’ll also see that the ‘Date Subject Created’ shows the PL5 bug of adding a ‘+00:00’ time zone in place of the ‘-07:00’ in the orginal NEF. However, the jpg no longer contains Legacy IPTC tags with the 5.1.3 update.)
I’m not sure how the metadata will show up in the tools you’ve been using. I’ve attached screenshots of my IM preferences for Metadata and Metadata 2.
Hope this helps! Let me know if you have questions.
John