Why does the matching users in a user segment show more than what is listed on the group or tags selected?
Other than the users matching the tag or group set in the condition, user segments also show users that have guide manager permissions on the list of matching users. Guide managers have full access to all articles in Zendesk Guide.
By default, administrators in Zendesk Support are Guide Managers. The team leader role also has a Guide manager privileges set. To modify agent access or roles for Guide, see the article: Changing an agent's role to grant Guide Manager privileges.