Resolution: This applies to the following message.
Client -- TIBCO ActiveMatrix (AMX) Application -- Target Service
Using out of the box policies, it is not possible to set the subject in the SAML token in the request being sent by a reference endpoint of an AMX Application, based on the information in the request received by its service endpoint. One option would be to use custom code to add the SAML Assertion in the component (Meditaion/Java) and then sign it using an out of the box policy.