Student or Learner
1) What is the career path for being Chef?
2) What does this sales position leads to?
3) What position does the sales position leads to?
Consider these changes:
1) What is the career path for
2) What does this sales position lead
3) What position does the sales position lead
In your first sentence, "Chef" must refer to the only chef position under consideration, for example, the one that is employed by the person who is being asked. Otherewise, it should read "becoming a chef".
In your second and third sentences, the second person is estalished by the use of "does". The response should be "The position leads to ..."
You might also consider using "will" instead of "does" if the person asking isn't currently in the sales position.