You can unpublish (i.e. hide) a chapter so that end users cannot see the content. This article will teach you how to make an unpublished/hidden chapter visible to your end users in your manual.
Publish a chapter
Unpublish the chapter

Updated Sep 10, 2020
You can unpublish (i.e. hide) a chapter so that end users cannot see the content. This article will teach you how to make an unpublished/hidden chapter visible to your end users in your manual.
@Annie - The unpublished option wouldn't be available if your site is connected to Zendesk. Is your site connected to Zendesk?
What happens if the ability to unpublish is not available?