Computer Configuration > Administrative Templates > Google Chrome > Sign-in settings
Both
HKLM\Software\Policies\Google\Chrome
If this policy is unset, account logins will not be required to create a new separate profile. If this policy is set, account logins from the listed domains will not be required to create a new separate profile. This policy can be set to an empty string so that all account logins are required to create a new separate profile. Example value: domain.com otherdomain.com