How do I fix a broken brass drawer pull?
You may be able to find some NOS (new old stock) pulls of the same type on eBay or Etsy. I recently did the same thing for an old writing desk that was missing one of the pulls. I couldn't find a match for the missing one, so I replaced the whole set.

If you want them repaired, then they will probably need to be brazed and re-tapped. That is a job that you should have done professionally if you aren't comfortable using a torch.

Brazing