It would help if you were more specific about where these documents come from. Do you mean pdf files?
So both files would need to be in the vault. And if the "Enterprise Published document" was created using the EPDM Convert task then an auto Paste As Reference piece of info can be placed in the file during the task. That must be set up in the task though. Otherwise there is no connection.
If you want to create that connection at any time then you can use Paste As Reference. 2014 SOLIDWORKS Enterprise PDM Help - Creating References
Thanks for response.
I have noticed "URL to SLDDRW" attribute in the published files. Can we directly access the CAD file using that URL?