How to notify workflow A currently in wait state from workflow B?

I have two workflows A and B. After certain steps in workflow A, I am initiating workflow B and setting the workflow A to wait for notification. When all the user tasks in workflow B are complete I want to notify workflow A to resume processing. I have two questions here. How to establish parent child relation between the two workflows. Do we have any OOTB way to achieve this? How to fetch the context of Workflow A from workflow B in order to notify it?
1 answers

I was able to fulfill the above requirements through following steps:-

  1. There is an association workflow_parentworkflow which can be used for establishing a parent child relation. In workflow B, I called microflow where I am retrieving the A workflow object and then setting it to the member workflow_parentworkflow of B’s workflow object.
  2. Here I am first retrieving the A’s workflow object from and filtering by X path. Then retrieving A’s workflow context using activity and the calling notify workflow activity.