Is it possible to make one note to belong to two hierarchies? For example, I have my literature notes in

book.subject.author.md

, but the same citation could be used in different project/articles i write. So I want

book.subject.author.md

to belongs to "book" hierarchy and to "subject" hierarchy. Or something like

project1.book.subject.author.md

and

project2.book.subject.author.md

but the same note. I doubt it's possible, but asking just in case. 🙂