Upon going to configure the Self-Help menu in the vFire Customer Portal, we've found that we can remove and hide fields (as per Admin response to CORE-I-406), but there's no ability to add any additional fields.
The ability to add additoinal fields to this screen would allow for customers to have greater control over filters, which will refine results and get them what they're after (rather than scrolling through many publshed articles). As we support multiple agencies, we have articles for specific procedures for a specific org - Allowing someone to filter by org, for example, would be fantastic.
I was honestly surprised hearing from our application support team that we weren't able to fully configure this screen. Please consider adding this as a standard feature.