Auto populate a form with data fetched from same form

Auto populate a form with data fetched from same form

I was working on this feature some time ago, never figured it out and moved on.

Now I'm revisiting this idea of auto populating my form of customer information that has been previously entered.
Additionally only pulling address that have been entered by the current logged in user.

Using  Auto populate a form with data fetched from another form I have tried to get this to work, however with no success.

Any direction or examples anyone can offer? 
Thank you