8.js

var collName= 20180419
// 2018-04-18 00:00:00 to
// 2018-04-18 23:59:59
var dateRange= {"$gte":1524009600,"$lte":1524095999}
// -----------------------------------------------------
var queryDoc08 = {}, segments = {"id": "5a709f20e8a46fcd9c0c5d37", "name": "_HAS ACTIVITY" } 
queryDoc08.last_request_at = dateRange
queryDoc08["segments.segments.id"] = segments.id
db.getCollection(`${collName}`).aggregate([{ $match: queryDoc08 },{ "$group": {_id: null,/* 'Plan Names': { $addToSet: { api_plan_name : "$custom_attributes.api_plan_name"}}, */ "Total Activity": {"$sum": 1} } } ])