Unfortunately this is not possible even with the new search card designed with OOTB functionalities.
Another way to get around is to browse to that location and initiate a search, by default the search path would be pointed to that folder
and you can enter the file name or file extension.
The only way currently i see is to have multiple search windows for different folders.
Hope this helps !
Thanks Raghav. I'll have to submit an enhancement request. This would be extremely handy.
I tried putting the "Search Folder Path" field and Browse button on the Search card twice, and each just update the other. Enhancement request will be needed unless you have a custom app written.