Need help in automation for jira with summ of original estimate in parent task

Question

Hello the Team, 
I need help)

We made an automation in Jira for summ of original estimate from subtasks to story and from tasks in erpic to epic

But

We have 3 situation, when we dont know how to automate

May be you have examples or detailed instrustion for it

Sub task changes parent link:
- need to recount original estimate for old parent and for new
For new - no problem, I done
For old - ???

Sub task change type to task without parent
- need to recount old parent ???

Task/story/bug change epic:
- need to update old epic estimate and new epic estimate 
For new - no problem, I done
For old epic - ????

John Driscoll_jo5pju · Answer

I'm wondering, if creating a 'linked issue' prior to converting the subtask might provide a method to obtain the original estimate of work?

Trudy P Claspill · Answer

I have not been able to solve that problem.

Before converting a sub-task to an issue, the sub-task's parent issue is noted in the {{issue.parent}} field.

If the parent issue was a child of an Epic, then when the sub-task is converted it is also made a child of the same Epic. That changes the value of the {{issue.parent}} field. Unfortunately the change to the field is made in two steps. First the Parent field is cleared, then the Parent field is set. I don't know how to parse the change log to get the information for multiple changes to a field.

Oksana Baier · Answer

Thanks a lot
I made rule for all cases except one:

When we move sub task to task - we cannot find previous parent task by

It is last case for my rule and I can share the rule for help of community, cos I saw many requests for this issue

How I can know parent link in this case? Can you help me? :)