BTRFS how to find the volume which is the parent of sub-volumes

Hi there !

Code:localhost:/home/miguel # btrfs subvolume list -t /var
ID gen top level path
-- --- --------- ----
256 1993 5 @
257 1997 256 @/var
258 1964 256 @/usr/local
259 1997 256 @/tmp
260 1888 256 @/srv
261 1964 256 @/root
262 1905 256 @/opt
263 1888 256 @/boot/grub2/x86_64-efi
264 1888 256 @/boot/grub2/i386-pc
localhost:/home/miguel #How do I know who is the parent dir (volume) of theses sub-volumes ?

I expect to see all theses sub-volumes as regular folders in the parent folder.

thank you in advance,