Loopback Mongodb Query

 var GroupCollection = User.getDataSource().connector.collection(User.app.models.group.modelName);
          GroupCollection.aggregate([
            {$match: {status: true}},
            {$sort: {updatedAt: 1}},
            {
              $lookup: {localField: "_id", from: "member", foreignField: "groupId", as: "members"}
            },
            {
              $group: {
                _id: "$_id",
                members: {$addToSet: "$members.userId"}
              }
            },
            {
              $project: {
                _id: 1,
                title: 1,
                members: {$arrayElemAt: ["$members", 0]}
              }
            },
            {
              $match: {
                $and: [
                  {members: {$all: paticipants}},
                  {members: {$size: paticipants.length}}
                ]
              }
            }
          ], function (err, result) {
            console.log("Found result", paticipants, result);


        });