Can I just clarify something to see that we are all agreed on it?
MWG Guidance indicates that the following is the correct way of recording a hierarchy…
<dc:subject>
<rdf:Bag>
<rdf:li>Animal</rdf:li>
<rdf:li>Mammal</rdf:li>
<rdf:li>Bear</rdf:li>
<rdf:li>Black Bear</rdf:li>
</rdf:Bag>
</dc:subject>
…
<lr:hierarchicalSubject>
<rdf:Bag>
<rdf:li>Animal|Mammal|Bear|Black Bear</rdf:li>
</rdf:Bag>
</lr:hierarchicalSubject>
This indicates that the “selected” keyword is Black Bear.
If a user were to select Mammal as well, then I believe the lr:hierarchicalSubject should then change to…
…
<lr:hierarchicalSubject>
<rdf:Bag>
<rdf:li>Animal|Mammal</rdf:li>
<rdf:li>Animal|Mammal|Bear|Black Bear</rdf:li>
</rdf:Bag>
</lr:hierarchicalSubject>
… or, if all nodes were selected…
…
<lr:hierarchicalSubject>
<rdf:Bag>
<rdf:li>Animal</rdf:li>
<rdf:li>Animal|Mammal</rdf:li>
<rdf:li>Animal|Mammal|Bear</rdf:li>
<rdf:li>Animal|Mammal|Bear|Black Bear</rdf:li>
</rdf:Bag>
</lr:hierarchicalSubject>
This then means that selected (applied) nodes can be identified from the XMP.
@Musashi does this make sense to you as well?