InfoPath Dev

 I currently am trying to set a textbox's value using a dropdown. The dropdown is pulling it's selections from a SharePoint list.  The issue is I always get the same value no matter what selection I make.  I have read many posts on this but cant seem to get it. 

Current XPath formula:  

xdXDocument:GetDOM("Vendor List")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:FullName

Thought for sure I tried this several time but I guess I didn't. 

xdXDocument:GetDOM("Vendor List")/dfs:myFields/dfs:dataFields/d:SharePointListItem_RW/d:FullName[../d:ID = current()] 

  I think I have tried current() in all places and with a variety of variants from examples online.

 Most common error:  does not point to a valid location path of a field or group. 

 Any guidance/ help would be greatly appreciated!

Thank you 

Hi - so this is a rule on the dropdown? and the dropdown uses the ID for it's value setting?

Sorry! just realized from your subject line change that you had figured this out on your own. :)

 No worries.  I appreciate you trying to help.  Thank you again!