Add sub-items columns on automation recipe for easy information

When i want to send custom message to my team member on slack for sub-items as:

Hey team {sub-item-columnName1} is reviewed and please check the task.
In this case, i am unable to add sub-item-columnName in the automation recipe as the auto populated columns are only of parent item but not sub-items. so here the custom free notifcation on slack gets failed and there is no use of sub-items columns in automation. It should be very crucial feature to be added.