Can a rhinoplasty and breast fat transfer be done at the same time?

Although you could have both procedures done at the same time I would advise against it. For rhinoplasty you need to find a really good rhinoplasty surgeon who might or might not want to do fat transfer. Rhinoplasty requires dedication and full concentration on the nose.

Short answer is yes.
You would need to be evaluated preferably by a board certified plastic surgeon who will review your medical history and your surgical goals. As long as you are a good candidate for surgery combining these 2 procedures should not present a problem.
Best of luck to you!