MongoDB 3.4 - get array of subdocuments without root document

Try this:

db.collection.aggregate([    {        $unwind: '$nodes'    },    {        $match: {_id: ObjectId("589eff3fee3d13019843f55a") }    },    {        $replaceRoot: { newRoot: "$nodes" }    }]).toArray();

And you will get

[    {        "_id" : ObjectId("589eff8f2bb59057c3f9b89d"),        "name" : "Node A"    },    {        "_id" : ObjectId("589eff962bb59057c3f9b89e"),        "name" : "Node B"    },    {        "_id" : ObjectId("589eff982bb59057c3f9b89f"),        "name" : "Node C"    },    {        "_id" : ObjectId("589eff9a2bb59057c3f9b8a0"),        "name" : "Node D"    }]

$unwind operator is to deconstruct nodes field from the input documents to output a document for each element.

And then use the $replaceRoot stage to promote the nodes document to the top level, discarding the current top level fields.

Hope this helps.

Here is how you can do this with aggregation (Mongo v3.4+):

db.projects.aggregate([	{$match: {_id: ObjectId("589eff3fee3d13019843f55a")}},	{$unwind: '$nodes'},	{$replaceRoot: { newRoot: "$nodes"}}]).toArray();