Managed Metadata - TermSets - Terms - Document Library

I can get all the terms/ termset from term store. I can loop through term group, term set and terms. However, I cannot find a way to see which fields are associated to which terms.

If I go through all terms from term store, Throttling comes in to play.

If there is a way just to find terms that is associated to a given document library, please point me to the right direction.

Thanks