Hi, I'm trying to create the hair for a character wich have two udim tiles, and I don't know how to apply the textures to a specifics udim on the groom tab, I only can apply one texture.. what's the workflow for multiple udims? or do I have to break down the object by udims and work on one udim only?

should be same as anywhere else
try replacing your udim number in the filepath with %(UDIM)d token

also
when you are picking the file using the file chooser you can check Show Sequences As One Entry and choose UDIM from the dropdown, that should populate the filepath with udim token directly for you

it work, thanks!!