[{"parentId":1,"name":[{"language":"en-US","text":"Book"},{"language":"fr-CA","text":"livre"}],"isActive":true},{"parentId":1,"name":[{"language":"en-US","text":"Pen"}],"isActive":true},{"parentId":1,"name":[],"isActive":true}]

db.collection.aggregate([{"$match":{"parentId":{"$eq":1}}},{"$set":{"name":{"$getField":{"field":"text","input":{"$arrayElemAt":[{"$filter":{"input":"$name","cond":{"$eq":["$$this.language","fr-CA"]}}},0]}}}}},{"$match":{"$expr":{"$eq":[{"$type":"$name"},"string"]}}}])