mongo_aggregate_and_filter

filter.js

/**
* This will filter down to the matches with a specific player, with the matches being played after a specific date,
* and it will show only the aggregate matches after that date ignoring the previous ones
*/
var dateFilter = new ISODate("2019-06-01T20:15:31Z");

db.getCollection('competitions').aggregate([
    { 
        $match: {
            players: ObjectId("5c71c4c1185c610046f17911"), 
            'matches.date': {
                $gte: dateFilter
            }
        }
    },
    {
        $project: {
            matches: {
                $filter: {
                    input: '$matches',
                    as: 'item',
                    cond: {
                        $gte: ['$$item.date', dateFilter]
                    }
                }
                
            }
        }
    }
 ])