… and apart from the “Bitwarden plans”… “vault item sharing” is on the roadmap, which also means not yet possible (only “indirectly” via collections or “Sends”…) - see here the roadmap: https://community.bitwarden.com/t/bitwarden-roadmap
PS: An entire discussion about this topic can be read here: Vault Item Sharing (and there it is tagged as “roadmap:planned”)