Stanley posted this on the old forum, Forum Post. He frames my question as well, so I repost it.

Hello. I am having a difficult time figuring out how to implement a conditional field using the state "is Filled by". As I interpret the brief instructions, you should be able to designate a source field to populate your conditional field provided your conditions are satisfied. The instructions say:

I have tried the ID, the Title and the name for my source field in this first inputbox, but without any success.

My condition is not the problem, as it functions correctly for an "is Filled" state with static text in the first box. The problem appears to be with properly referencing the source field in the "is Filled by" state.

I would certainly appreciate some additional clarification about how one might conditionally pull the value from another field in the same form. Perhaps I have misunderstood the function of "is Filled by"

.... DITTO!

This is very useful if, e.g. someone Checks YES if their shipping address is = to their billing address... if I understand the proper use of this conditional feature correctly.