Dividing surfaces with curves?

 From:  Michael Gibson
5220.3 In reply to 5220.1 
Hi Dreamcube017 - yup like Pilou says you want to use the Edit > Trim command for that kind of surface-level cutting. It will slice only the surface of your object up into pieces instead of working at a solid volume level like the booleans are targeted at.

See here for a previous example similar to what you are describing and some description on how to use Trim:

- Michael