If your organization has a multi-domain environment, you need:
1. The administrators of the Active Directory of the organization, need to create a trust relationship between the domains to allow authentication of users from all domains.
2. In this LDAP data source, select Use GSSAPI SASL authentication mechanism to connect to the LDAP server with SASL binding with GSSAPI authentication mechanism, instead of “simple binding”.
You can refer to this document below:
Hope this helps!