Use the Files Related List for Knowledge Articles in Communities
Where: This change applies to Lightning Communities with Lightning Knowledge enabled. Lightning Knowledge is available in Essentials, Professional, Enterprise, Performance, Unlimited, and Developer editions with Service Cloud. Salesforce Knowledge is available in Professional, Enterprise, and Performance editions as an add-on.
Who: Internal community users can see files uploaded to a Files related list for a Knowledge article that they can view. External community users see files uploaded to a Files related list when the visibility is set to AllUsers, and they can view the associated Knowledge article.
How: In Community Builder, add the Record Related List component to an Article Detail page.