This document explains on how to export K2 item with extra fields.
- In K2 extension, create two extra fields of type Text and Multi-select. Let's name them as Product extra notes and Product colours.
 - Add a value to extra fields for a K2 item.
 - Run update of available fields in RO CSVI.
 - Create K2 Item export template.
 - From RO CSVI template fields add needed fields. In this example we have add alias, category_path fields along with K2 extra fields Sample group_Product colors and Sample group_Product extra notes.
 - Run the export. Kindly note that multiple values of extra fields are separated by | in export file.
 
Video showing the process