It is not possible to configure Contract Management to connect \ integrate with more than one LDAP authentication server.
This is an existing Enhancement Request:
Bug 9724986 15 ABILITY TO ENTER MULTIPLE LDAP SERVERS FOR CONTRACT MANAGEMENT
The Primavera Administrator only supports variables for a single authentication mode and authentication server.
Reference: Note 913872.1 How To: Configure / Enable LDAP Authentication using the Primavera Administrator (admincm.cmd)
This sounds like short term requirement, however, if you would like to be included on the related Enhancement Request, please create an SR to request your organization be added to the Enhancement Request.