$ uname -r
4.18.0-425.13.1.el8_7.x86_64

$ rpm -q coreutils
coreutils-8.30-13.el8.x86_64

$ mkdir -p /original /bind1 /bind2

$ mount.nfs server:/nfs /original -v     
mount.nfs: timeout set for Fri Mar 10 10:50:59 2023
mount.nfs: trying text-based options 'vers=4.2,addr=192.168.122.40,clientaddr=192.168.122.121'

$ mount --bind /original/testd1 /bind1 -v
mount: /original/testd1 bound on /bind1.

$ mount --bind /original/testd2 /bind2 -v
mount: /original/testd2 bound on /bind2.

$ df -ht nfs4                            
Filesystem          Size  Used Avail Use% Mounted on
server:/nfs          97M  5.4M   92M   6% /original
server:/nfs/testd1   97M  5.4M   92M   6% /bind1   
server:/nfs/testd2   97M  5.4M   92M   6% /bind2   

$ mount --bind /original/testd1 /bind1 -v
mount: /original/testd1 bound on /bind1.

$ mount --bind /original/testd2 /bind2 -v
mount: /original/testd2 bound on /bind2.

$ df -ht nfs4
Filesystem          Size  Used Avail Use% Mounted on
server:/nfs          97M  5.4M   92M   6% /original
server:/nfs/testd1   97M  5.4M   92M   6% /bind1   
server:/nfs/testd2   97M  5.4M   92M   6% /bind2   
server:/nfs/testd1   97M  5.4M   92M   6% /bind1   <--- dup
server:/nfs/testd2   97M  5.4M   92M   6% /bind2   <--- dup

$ cat /proc/fs/nfsfs/volumes 
NV SERVER   PORT DEV          FSID                              FSC
v4 c0a87a28  801 0:55         8d133867f8e04cf9:984d43c5f2b82b17 no 

$ grep 0:55 /proc/self/mountinfo
423 97 0:55 / /original rw,relatime shared:219 - nfs4 ...
421 97 0:55 / /bind1 rw,relatime shared:219 - nfs4 ...
439 97 0:55 / /bind2 rw,relatime shared:219 - nfs4 ...
449 421 0:55 / /bind1 rw,relatime shared:219 - nfs4 ...
459 423 0:55 / /original/testd1 rw,relatime shared:219 - nfs4 ...
502 439 0:55 / /bind2 rw,relatime shared:219 - nfs4 ...
503 423 0:55 / /original/testd2 rw,relatime shared:219 - nfs4 ...