Where does iCloud saves backups and documents? I can't find them

Please see the image below. I am using 5GB of iCloud space, it shows 966GB of backup of my old iphone in iCloud. The storage is the same the yellow in the horizontal bar. The problem is I cannot locate this on iCloud. I logged into icloud.com but it is not there. The same is the story for documents which is taking about 900MB space on iCloud but I cannot find it. The question how can I download them, where can I find them. I can delete it but I do not want to delete without backing it up first. Adding a second screenshot, if I delete the whatsapp data, it gives me a message that it will be deleted from iDrive but the problem is I can't find it there hence can't back it up.