When importing domain users and groups, the user names and group names are compared with existing vault server users and groups. If a vault server user account or group already exists with the same name as the imported domain user or group, you are prompted to link the existing vault server account with the imported domain account.
The Linking Users and Groups dialog lists the domain name and the matching vault server name that will be mapped to it. You can accept or reject any of the proposed mappings. All mappings are accepted by default.