This is a customer requirement and you’re trying to do this at runtime? What I can’t wrap my head around is why this is a requirement? Most of the time the end user doesn’t need to know or even care about where the tags are used. Or even that there are such things as tags.
I can of course understand wanting a cross reference from a designers point of view, it’s been an often requested feature for sometime. The implementation of such a feature is...shall we say far from trivial.