In the creation of Help items, you are able to control where the Help item appears by limiting its scope. There are pre-defined scopes available in the Filters / Targets section of the Help Item tab within the SharePoint Online application:
You can accomplish the same thing using a URL Filter:
If you click on the URLs that begin with drop down, these are your options:
URLs that begin with, URLs that end with, and URLs that contain are straightforward and self-explanatory. But what if you have a more complex situation? For example, let's say you want to have a Help item appear on every page of a Wikipage library named "oursites" except for a page called "externalusers".
If your situation is similar to the example above just copy and paste this regular expression into the URL Filter 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: