We can view the complete message flow in Flow Trace window,while testing any SOA Composite from Enterprise Manager. By default, in Flow Trace window, we cannot view the input and output payloads for Mediator component. The reason for this is the Composite Audit Level is with Inherit value.
To view the input and output payloads for Mediator and few other components we need to change the Composite Audit Level is to Development value. This is used for testing and debugging during Composite development. This setting need to done in Enterprise Manager by selecting the SOA composite on the left side. This is only to SOA Composite level. If you want to change to other Composite you need to select it on the left side and need to modify the settings as shown below –