How to declare a relationship for nested object inside array

MongoDB Atlas App Services & Realm
1

if we have a object like this

{
   "title":"Company",
   "properties":{
      "_id":{
         "bsonType":"objectId"
      },
      "name":{
         "bsonType":"string"
      },
      "user":{
         "bsonType":"objectId"
      }
   }
}

i can link “user” with users collection by declaring in relationship with:

{
   "user":{
      "ref":"#/relationship/mongodb-atlas/{dbname}/users",
      "foreign_key":"_id",
      "is_list":false
   }
}

but if i have a object link this:

{
   "title":"Report",
   "properties":{
      "_id":{
         "bsonType":"objectId"
      },
      "title":{
         "bsonType":"string"
      },
      "days":{
         "bsonType":"array",
         "items":{
            "bsonType":"object",
            "title":"DayWork",
            "properties":{
               "id":{
                  "bsonType":"string"
               },
               "dayName":{
                  "bsonType":"string"
               },
               "notes":{
                  "bsonType":"array",
                  "items":{
                     "bsonType":"object",
                     "title":"DayNote",
                     "properties":{
                        "id":{
                           "bsonType":"int"
                        },
                        "task":{
                           "bsonType":"string"
                        },
                        "project":{
                           "bsonType":"objectId"
                        }
                     }
                  }
               }
            }
         }
      }
   }
}

how can i link report.days.notes.project to projects collection with a relationship ?