Second portfolio Onigiri theme

Hello, I am working with Onigiri theme and it’s a lovely theme to work with :) I saw that it’s possible to create a second portfolio on the Baylys theme from a post by Ellen, and would like to do the same with this. I can’t quite figure out the files to copy though – do i need to copy content-portfolio.php / content-portfolio-single.php or actually to copy the portfolio-page.php too? I think I’m getting confused by the Jetpack portfolio files and not sure if i need to copy them as well… if you can point me in the right direction I would be so grateful. Thanks so much x