Prefix and path for file-based backups has been removed quite some time ago. Instead we use the path configuration from the HANA database itself and are using a fixed prefix "SnapCenter". I don't know exactly with which release the change came in. I looked at a SC4.5P2 installation and this configuration is not there anymore. You said your are using SC4.5, right? Did you make the screenshot for the file-based backup configuration with the same release?
Is it only there for the naming of the backups? Is that path definition not used for block integrity checks? I have checked and that "location" is not being used in the naming of backups anywhere. I understand that in order to gain some deeper information about this is to raise a case directly but there is not really a case here - its a P4 query at most. Is it possible that this parameter should have been removed from the "Add SAP HANA Database" like it was from the "Modify"?