If you refer to a list (as you are in the link in you RG cell) then you’ll get a list. By default that list will display in a single line with a comma delimiter, unless you format it otherwise.
What you need to do is refer only to the current cell’s file (as you have in the file name text box). So use current cell's file's URL
If you’re only seeing 1 file name when you run the page, then your datasource must only be returning 1 file (either that or only one of the files has a file name).
My guess is your search is wrong. What are the current constraints on your search for files in your RG?
Having said that, it looks like you don’t need to do a search anyway…
Your page seems to have a content type of ‘bid_request’, which has a field ‘FileList’, so it would be more efficient to refer directly to the page’s bid_request’s FileList, in the RG datasource.
And you know that’s working with the 2 files as they’re both showing when you referred to that within the RG cell.
So the correct way to achieve what you’re trying to do is use current page's bid_request's FileList as your RG datasource, and inside the cell, display the current cell's file's URL (and any other data relating to the current cell’s file)