When the search names a file, a line starting with Last change to shows when it last changed, who did it and what was done, and that entry opens by itself in the panel on the right.
Click any row to open it: Files changed lists the files in a table, with the ones matching your search highlighted, and pointing at a row shows its full path. Agents ask the same question with recent_changes, optionally for one path, which returns who changed which files with which operation, newest first, for up to the last 14 days.
A change made directly by FTP or by the site itself has no entry in recent_changes and no author in Activity; on a project whose source authority is SyncNow it appears only as an entry saying that changes made outside SyncNow were detected on the hosting. These views tell you who wrote and when, not what the content was; for previous content, see Can I get back a file that an agent overwrote?.