The search also looks at the files of the work sessions on the SyncNow server, across the project's history, so you find the work that touched that file, newest first.
At the top of the list appears Last change to followed by the file, for example Last change to includes/cart.php, with when, who and what was done. That entry opens by itself in the panel on the right, with the row of the file you searched highlighted in Files changed, its icon and name in green, even beyond the first 11 files, and pointing at that row shows its full path. Open this change, under that line, opens the entry again.
It finds changes made through SyncNow: an edit made by direct FTP or by another tool belongs to no work session. To see or restore the previous content of the file, ask an agent: see Can I get back the previous version of a file an agent changed?.