Holy,
The way the Endpoint agent works, is when a File or document is sent to the OS print spooler, the DLP agent intercepts that transmission and will then inspect the contents and compare that to the policy. So it will then trigger an incident on the match of the policy.
The incident in the DLP console will be able to tell you the filename and the matched content.
This should be more than enough information for you to need.
Is there more information you need?
PLease call it solved otherwise.
Ronak