hi, in 2019 summit and in an exclusive first look into zbrush development video, he goes to UVMAP> morph UV and sculpt on unwrapped version of model and when bring the object to 3d form sculpt is still on it. but when i try to do that steps in 2d form vanishes. i wanted to know how they do that? thanks.
Hello @Safdar_Safdari
I’m assuming the feature you’re referring to starts around here in the development video.
This is identified as a new feature in development, and not yet in the current version of Zbrush.
You’ll have to wait a bit longer to play with that one. 
Actually I meant when he unwrapped the shirt and sculpt seam on it where sleeve was in a position that in normal way you couldn’t reach there, a little after you are referring. But I think it’s development phase as you said. Thanks for your answer.
Yes, he starts around there showing how the feature can be used with polypaint, then for the finale shows how it can be used with sculpting.
You can paint color on a texture applied to a flattened UV layout already, with some limitations, using ZApp link or Projection Master. The sculpting thing you’ll have to wait for.
Thanks again, I found some post in zbrush central that was to sculpt on uv then capture displacement map to somehow do that.