Group by aggregation

// let timeline = await Timeline.aggregate([
    //   { $match: { timelineTopic: timelineTopic } },
    //   {
    //     $group: {
    //       _id: "$date",
    //       shortDescription: { $addToSet: "$shortDescription" },
    //       longDescription: { $addToSet: "$longDescription" },
    //       articles: {
    //         $push: "$article",
    //       },
    //     },
    //   },
    //   { $unwind: "$shortDescription" },
    //   { $unwind: "$longDescription" },
    //   {
    //     $project: {
    //       _id: 1,
    //       date: "$_id",
    //       shortDescription: 1,
    //       longDescription: 1,
    //       timelineTopic: 1,
    //       articles: 1,
    //     },
    //   },
    // ]);