You apparently select Recents and then initiated a search.
Click the x in the search box to cancel the search and show all the contents of "Recents".
FWIW, the "Recents" option in Finder does not offer any user control and, as such, is not something that is useful per se. You get all sorts of stuff. For example, I just turned on Recents and it says 20750 items. Way too much to easily find things. Amongst these "Recents" there are files from... 2018. Recent????
You could instead do your own Smart Folders and get finer control over what you see in there.
For example:

Save this and you can have all your pdf modified in the last five days right there in the sidebar.
Or image files that are jpg and at least 4000 pixels wide,
or... you define the criteria, not some jumbled up "recents" that can be anything.