IPTC / Write Metadata to File ... Preserve hierarchy?

If I used a sidecar/xmp, Digikam writes the hierarchy of tags perfectly, in multiple forms:

     <rdf:li>:in depth/:: style or aesthetics/anime</rdf:li>
     <rdf:li>collection/- IP or Universe/::: game</rdf:li>
     <rdf:li>:media/pixelart</rdf:li>

But in-file, using IPTC it only writes out the selected hashtags and not the hierarchy:

::: game
anime
pixelart

Is there any way to preserve this hierarchy when writing to file?

Thank you!