BUG #16234: LDAP Query

The following bug has been logged on the website:

Bug reference:      16234
Logged by:          Sujith kumar
Email address:      sujiplr@gmail.com
PostgreSQL version: 9.5.20
Operating system:   RHEL 7.7
Description:

Hi Team,

I have a requirement to do authentication through LDAP, the LDAP query
should go to two different LDAP servers with dedicated binding users (
different for two LDAP servers) , if the user is not available in first LDAP
then it should check in second LDAP. But here as per hba file , it won't
work in this model ( If there is no successful search in first hope, it will
throw error). 

So we have to do multiple query in the LDAP query string, how we can do
this? 

Regards,
Sujith Kumar.S