BW has an explicit trust model that requires a whole chain to be available in a Trusted Certificates folder.
Often the root CA does not exist in a BW trusted certificate folder and the Server sends a full chain in the handshake, as a result the handshake fails. In order to pass the path validation, you can use the following BW property in the application tra file:
java.property.com.tibco.security.NoExplicitCAChain=true
Explaination: In general BW has an explicit trust model. i.e. client would only establish an SSL connection if it was able to verify a full chain of trust from the server's certificate to a root certificate. By setting NoExplicitCAChain to true, we can work around the explicit model, which will not require the full certificate chain to be present.