Find DLP matching policy

I have multiple DLP policies created in my tenant. One of the policy block all file sharing with external users. I only want to stop sharing files if the file contains sensitive data, such as SSN. I would like to find out which one of the policies match that criteria so I can modify that policy accordingly. But how do I know which DLP policy matches. I have looked at the DLP report, but it is not real time report.

Thanks in advance, 

Peter