External lookup - passing dependency using Workfront Planning api

I’m trying to create two external lookup fields that are using the Workfront Planning api to pull data from Planning.  I’ve created my first lookup fine and its pulling my Planning fieldId with the records I want to show users.  The fieldId output from this first field will drive what records a user sees in the second external field.  The Workfront Planning api uses JSON for filtering, which is curly brackets, and the dependency field needs curly brackets around the field you need the dependent output from.  What’s happening is when I try to build the filtering for the 2nd external field to use the output I need, it needs to be written in JSON so the dependency field is put everything in curly bracket if that dependency field, which obviously is not working.  Has anyone worked with Planning api within an external field to get a dependency, coming from another Planning field to work?  Any insight, ideas, or thoughts would be appreciated.