How to use getFields with nobrainer

Question

I started learning rethinkdb and can't replicate a query that I need using nobrainer+rails.

In the RethinkDB data explorer the query is working (not sure if optimal) but it returns the required result.

    r.table("apps").get("1").pluck({'releases':['job_id', 'dists']})
    .getField('releases').filter({job_id : '832'})

which returns

[
 {
 "dists": [
   {
   "checksum":  "3333333" ,
   "type":  "debug"
   }
  ] ,
  "job_id":  "832"
 }
]

The data that is being queried basically is

{
"id":  "1" ,
"name":  "blah" ,
"releases": [
   {
   "branch":  "master" ,
   "dists": [
      {
      "checksum":  "3333333" ,
      "type":  "debug"
      }
   ] ,
   "job_id":  "832"
   } ,
   {
   "branch":  "master" ,
   "dists": [
     {
     "checksum":  "3133333" ,
     "type":  "release"
     }
   ] ,
   "job_id":  "831"
}

Any clues on how to get the same result using nobrainer+rails? I know I can create new modals for releases and use the :has_many... But I would like to know how can accomplish that with this data structure.

Thanks!