Create a new local variable named partnerlink_reference. The schema of this variable is an element called service-ref, which is defined in Service Reference Schema for WS-BPEL 2.0 (http://docs.oasis-open.org/wsbpel/2.0/serviceref). This element is used as an envelope to wrap the endpoint reference of a partner link. Here, we use WS-Addressing schema (http://schemas.xmlsoap.org/ws/2004/08/addressing) to represent an endpoint reference, as shown in the following screenshot:

Drag-and-drop a new assign activity in between the <assign> activity named initialize_input_variable and the <invoke> activity named invoke_search_web_service. This assign activity is used to initialize the variable that holds the endpoint data and then that value is assigned to...