CMMN How to execute a Case Task while maintaining the InstanceId of the parent flow

How you could during the execution of a flow, call a Case Task where, when running the same, keep the businessKey and the instanceId of the main flow.

I have a very huge flow and I want (need) to make “divide and conquer” in order to make easiest the implementation and testing. I tried to make smaller flows and used case task, but when a case task activates it changed the caseInstanceId and then I have no way of known what task are executing or what is their state.

Anyone can help me?

(sorry if my english is not very good)

You can define the business key of a called process or case instance in XML. Furthermore, you can use an expression to copy the business key from the calling to the called process or case instance. See https://docs.camunda.org/manual/7.7/reference/bpmn20/subprocesses/call-activity/#passing-business-key for an example.

You can’t copy the instance id, though, as those are generated by the engine and required to be unique.