I was trying to post this in the below topic, bu it is not available for selection:
This feature is nice, however along with that ability to keep part of the article "public" is required.
Here is use-case:
1. 90% use Google to search.
2. In most of the cases you will be likely not logged in to Zendesk
So if there is an article that is available, you will just not find it because of above.
Part of the article e.g. with "Question" section is available always, but "Answer" is only available when you logged in and have permissions as per User Segment.
The same approach used for RedHat knowledge base e.g.