query.js

let groupQuery = [ 
  { 
    $group: { 
      _id: { repo : "$repo", type: "$type" }, 
      count: { $sum: 1 } 
    } 
  }, 
  { 
    $sort: { 
      "count": -1 
    } 
  }, 
  { 
    $match: { 
      count: { '$gte': 3 }, 
      '_id.type' : 'WatchEvent' 
    } 
  }
];