[{"_id":ObjectId("628be38c81f6e31196b6148b"),"items":[{"shape":"circle","color":"blue"},{"shape":"square","color":"red"},{"shape":"triangle","color":"yellow"}]}]

db.collection.aggregate([{$match:{"items.shape":"circle"}},{$unwind:"$items"},{$match:{"items.shape":"circle"}},{"$replaceRoot":{"newRoot":"$items"}}])