SharePoint repository scans with REGEX filtering

We would all love to scan EVERYTHING in a SharePoint repository, but quite often we need to scan based on one particular path. As SharePoint can be configured many different ways, a REGEX query not always get the right results the first time, which can result in a scan that is too broad, or a scan that indexes nothing - therefore a number of trial and error repositories or rescans.

Question:

Is there a way to perform the regex to confirm the results fall under the path designated prior to the CP indexing?  Either within CP or external?

Example:

SharePointURLType=SiteCollection

SharePointURL=ARealOnline.sharepointsite.com/.../

ListItemPathMustHaveRegex=https://ARealOnline\.sharepointsite\.com/sites/sitename/doccenter/folderInDocCenter/?

When we adjust to try different REGEX filters, we would like a more clear way to see that the REGEX is correct.

Thank you!