Filter by attachments

In one Password 8 under categories there is a category called Documents everything in documents is an attachment (file).
All Items is mixed everything.
So would not documents be what you want?
In documents it shows the file name so you can scroll to the file you want.
If you do not see documents then maybe it is, because you do not create tags.
If you create tags for attachments (files) only then you already know that every tag has an attachment.
Let the tag name be your folder category and whatever you name the attachment is how you know what the specific file is.
Personally I never go to documents and instead go to tags, but documents sounds like that is what you wanting and it is there already.