recover Date using Hierarchy Function

[#1]

Hello,

I am trying to build a monitoring on the execution Qlikview Tasks. For that I use the logs "Trigger.xml".

Trigger in my many tasks are "event is from Reviews Reviews another task" so I had to use the function "Hierarchy" to retrieve data son and parents.

what I want to do is give the date "StartAt1" of the parent to son.

as the example image below

'

????

regard