The way it is done in the video is using a custom reference to object field called "Original Parent". The custom action then does the following:
Updates the field "Original Parent" with $Parent
Uses the Move Object action, where the selected work item = currentobject() and New Parent Work Item = iteration variable (the iteration or work item entered in the custom action popup).
There is then a workflow rule that runs as follows:
Run time every time a record is created, or when a record is edited and did not previously meet the rule criteria
Evaluation criteria set to check if the Original parent is not equal to null ($C_OriginalParent<> null && $C_OriginalParent<>$Parent)
New Object action that creates a new shortcut, and sets the parent = $C_OriginalParent and the Child = currentobject()
Here's a link to install the application: https://app.clarizen.com/clarizen/View/Default.aspx?id=ac7fc8db-3620-4a82-a3c3-acba17df1795&type=Published+Application
Let me know if you need any help.