Dynamin Parallel process query

Hi BPM Experts,

We need to implement dynamic parallel flows using SAP BPM. In these parallel flows, if 1 person rejects, all parallel tasks should get cancelled and the request should go back to the requester. 

I managed to implement the dynamic parallel flows and also, if 1 person rejects, its possible to cancel all the parallel tasks. This can be achieved
using Referenced subprocesses inside a BPM Process. The scenario looks as

Main ParallelCheck Process

Referenced ParallelCheck1 sub process

But I am stuck at – how to return the flow back to the parent BPM process from the sub process so that the request can go back to the requestor or at least continue in the main process. In ParallelCheck1, I hit a terminating event (to simulate 1 approver cancelling). But this terminating event does not pass any token back to Parent process – ParallelCheck. As a result, the process gets stuck in ParallelCheck (step marked in red).

I have already tried invoking Boundary conditions, but still the parent process does not wake up.

It will be really helpful if you can suggest any options either to recover the parent process or alternative to implement the above scenario.

Thanks in advance.

Best regards,

Nakul