Multiple users with the same OTP Token
At this time it is not possible for more than one AD user account to share a single token. In cases where it would be inconvenient for one human to carry multiple YubiKeys (such as administrators with many accounts) then it may be more sensible to create OATH soft tokens for some or all of the accounts. Since they are displayed in separate rows in the Authenticator app, having a sizeable number of tokens is still completely reasonable.
If you want to use one hardware token for many accounts, you can also use an OnlyKey.