This is more complex than you might imagine. Word does not track "Chapters" as such. Your chapters are probably (I would hope) designated by a multilevel list linked to heading styles.

To do this you would need to find the bookmark and then relate that to the previous heading.

The macro at https://www.msofficeforums.com/vba/1...bookmarks.html may help you get a start. Also Greg Maxey and Graham Mayor have bookmark utilities on their sites that might give you help.