Calibre assumes identifiers are generally unique, so it doesn't have a quick link for that.
But you can search Calibre for the story URL identifier with:
identifiers:"=url:http://test1.com?sid=2"
Replace the italicized part with your story URL.
Since you apparently have a number of them, I would suggest using the
Find Duplicates plugin--it has a mode specifically for finding duplicate identifiers.