Using UD2-UD8 Defaults on UD1 Members

I am trying to utilize the UD2 and UD3 Default Member fields on UD1 members.  For example, I have UD1 members that always go to a specific State.  Nothing is showing up in UD2 for the State after transformation.  Also, I'm not sure how to set up the Data Source for UD2 when utilizing this field since UD2 does not relate to the imported file.

 

From the Reference Guide

UD2-UD8 Default
This is the standard default Member that can be mapped for a setting and saves having to map to
each Member. If the setting says Default, the mapping will always go to that default.

 

Any help on utilizing these fields is appreciated.  thanks