Answer for How to duplicate portfolio section that can be accessed separately through the header menu?

Hello, the following is the steps you need to do.
For back-end

  1. Create a new post type for the duplicate section. Open the file “inc\post-types\register-portfolio.php”, create a new post type (i.e. project) refer to the existing codes (line 3-19 ). 
  2. Add new setting area for the duplicate section. Open the file “inc\redux-config.php”, add setting area for the new section refer to the existing codes (line 281-320 ).

For front-end
Open the file “template-home.php”, get the new post type posts and display them refer to the existing codes (line 76-204 ).