Mongo DB distinct values group within array of objects
name field should be inside group stage, that's why you have error.
Try this query:
db.getCollection('products').aggregate([ { $unwind: '$features' }, { $unwind: '$features.values' }, { $unwind: '$features.values.values' }, { $group: { _id: "$features.values.name", values: {$addToSet: '$features.values.values'} }, }])Result:
{ "_id" : "feature2", "values" : [ "nest", "guest" ] }{ "_id" : "feature 1", "values" : [ "best", "test" ] }