Hi @Dan O Connor 
It may not be proper word "dot walk" for this case, but I want to create onChange client script of table A fields which works in the view of table B. 
This cause is not its script because it doesn't work inspite of the script is only for addInfoMessage as a test.

The root purpose is to automatically set the group reference field of table A by manually setting the user reference field of table A in the view of table B.
So I need the onChange interaction of two fields of table A in the view of table B.