Render Additional Output - Set file names?

Hi again.

When creating an additional output, there seems to be no way to set a file name for that output. Instead, bizarrely, I'm asked to set a subfolder. If the two outputs are of the same container format, I am forced to create a subfolder, rather than just simply providing a different file name.

I've looked at the More Options under the File section, but couldn't set unique names to each output without needing subfolders.