[{"location_identifiers":[{"permalink":"olivette-missouri","uuid":"e1774b1c-634d-4ea4-1414-cd8be15df631","location_type":"city","entity_def_id":"location","value":"Olivette"},{"permalink":"missouri-united-states","uuid":"51a065b8-05d5-1a28-3fcd-1ad143f1f725","location_type":"region","entity_def_id":"location","value":"Missouri"}]}]

db.collection.aggregate([{"$match":{}},{"$set":{"location_identifiers":[{"$arrayToObject":{"$map":{"input":"$location_identifiers","as":"item","in":{k:"$$item.location_type",v:"$$item.value"}}}}]}}])