Hi for cine lenses do most people use a UV filter for protection or is a clear nano filter a better choice?

Either or neither!

With your investment in gear, you do want only a very high quality filter. B+W or Hoya multi-coated. Hoya used to be a step down, but with their new coatings they are very good quality too.

A clear filter will reduce some UV.

A UV filter will tend to every-so-slighly tame sky. Not so you'd notice, really. I use UV filters on most of my lenses.

Either will work fine.

If you avoid harsh environments and can keep children's fingers off the lens no filter at all is fine. However, if the odds catch up with you and you take a pebble to the lens or something similar, you might be wondering why you didn't spend the few dollars on protecting your $5000 18-80 cine servo lens....