All files attached in the forum are saved into WordPress Media Library. But, if you want to see only attachments, you can’t do that directly, since Library show all files saved. Toolbox plugin has own panel called ‘Attachments’ where you can see only files uploaded as attachments. You have there: thumbnail preview, name of upload, topic and forum where the file is attached and date and time. This grid shows all files. You can delete or unattach files. If file is unattached, it will be removed from topic/reply it was uploaded to, but it will be still in the media library for some later use.