Hope you are looking for  the API for retrieving the history data. If you want to access the histry log provided by the JBPM you can use the below code

//Enabling the history Service 


JPAWorkingMemoryDbLogger workingMemoryDbLogger =  new JPAWorkingMemoryDbLogger(knowledgeSession);


// Get the JPA interface for History service 


JPAProcessInstanceDbLog historyService = new JPAProcessInstanceDbLog(knowledgeSession.getEnvironment());

The JPAProcessInstanceDbLog gives the API for retrieving the available history related data

Another way to implement your on history log is to implement the ProcessEventListener , check the documentation for more details.

Cheers

You can look at Business Activity Monitoring capabilities of jBPM5 that is embedded in console as well. Here you can find some details about BAM in general and here about its integration with jbpm-console.

HTH