child relationship in UI-Field

How would I place a child relationship field in a UI-Field if the name of the child relationship in the model is: {{Engagement_Roll__r.Roll__c}}

Global merge syntax can go through the child relationships and get data down there.   Here is an example: 


Let me break that down: 

  • Go to the Account model. 
  • Get the first row of data
  • Get the Contacts child relationship - and look for its records
  • Get the first row of data from within the child relationship records
  • Get the Created Date field…

Here what I am trying to accomplish. I would like to show in a reference field look up a UI_Field Long Text Area using the following. It looks like UI-field does not support "Long Text Area?