Answer:
they both fall under the category "benzodiazepines" which is a category on most drug tests, but a lab can easily figure out what drug triggered the benzodiazepine reaction.
most drug test will be testing for the ingredients of the benzodiazepines, not the drug it came from. a much more advance and expensive test would be required to determine if it came from xanax, koltipin or Valium because they are all benzodiazepines. This came from a doctor.