See how it works here.
If your situation is similar to the example above just copy and paste this regular expression into the URL Defined Scope field in your environment and replace "oursites" and "externalusers" with whatever words that will correctly filter your Help item. Also, keep in mind that this regular expression is case sensitive.
To exclude a page (in this example, office.com), use this regex:
Updated on April 3, 2020