Example usage of the SFDC Create-Job usage.

gistfile1.xml

<batch:step name="Batch_Step1">
	<batch:commit size="1000" doc:name="Batch Commit">
		<data-mapper:transform
			config-ref="Pojo_To_List_Order_Line_Items__c__1Pojo_To_List_Order_Line_Items__c__2"
			doc:name="Pojo To List&lt;Order_Line_Items__c&gt;"/>
		<set-variable variableName="batchPayload" value="#[payload]" doc:name="Variable"/>
		<sfdc:create-job config-ref="SalesforceOrderConfig"
			operation="upsert" type="Order_Line_Items__c" doc:name="sfOrderJob"
			externalIdFieldName="EXT_OrderShipToLine_Number__c" />
		<set-variable variableName="job" value="#[payload]"
			doc:name="Job Variable" />
		<set-payload value="#[flowVars.batchPayload]" doc:name="Set Payload" />
		<logger level="INFO" message="Upsert Lines job id: #[flowVars.job.id]"
			doc:name="Lines JobId logger" />
		<logger message="SFDC Order Lines Batch Incoming Payload:  #[payload]"
			level="DEBUG" doc:name="Order Line Batch Logger" />
		<logger message="SFDC Order Lines Batch Starting:" level="INFO" doc:name="Order Line Batch Logger" />					
		<sfdc:create-batch config-ref="SalesforceOrderConfig" doc:name="sfOrderLineBatch" >  
	    		<sfdc:job-info ref="#[flowVars.job]" />
	    		<sfdc:objects ref="#[payload]"/>
		</sfdc:create-batch>

To use Relational fields in SFDC. In Datamapper, manually create an Element with the __r field, and then the related field as an attribute of that Element.