By creating a Custom Specific Domain Audience you can specifically target certain articles within a webpage, up to 20 subdirectories per domain. For example, https://nypost.com/2020/08/17/didnt-take-long-for-giants-saquon-barkley-to-impress-joe-judge/. Specific domains will only target these exact pages and not the other pages that fall into the category subdirectory.
Enter each Specific Domain on an individual line in the ‘Custom Audience’ text box. This Audience has a limit of 50,000 Specific Domains per list.