[{"_id":1,"item":"abc","name":"Michael","price":NumberDecimal("10"),"quantity":NumberInt("2"),"date":ISODate("2014-03-01T08:00:00Z")},{"_id":2,"item":"jkl","name":"Toby","price":NumberDecimal("20"),"quantity":NumberInt("1"),"date":ISODate("2014-03-01T09:00:00Z")},{"_id":3,"item":"xyz","name":"Keith","price":NumberDecimal("5"),"quantity":NumberInt("10"),"date":ISODate("2014-03-15T09:00:00Z")},{"_id":4,"item":"abc","name":"Dwight","price":NumberDecimal("5"),"quantity":NumberInt("20"),"date":ISODate("2014-04-04T11:21:39.736Z")},{"_id":5,"item":"abc","name":"Ryan","price":NumberDecimal("10"),"quantity":NumberInt("10"),"date":ISODate("2014-04-04T21:23:13.331Z")},{"_id":6,"item":"def","name":"Jim","price":NumberDecimal("7.5"),"quantity":NumberInt("5"),"date":ISODate("2015-06-04T05:08:13Z")},{"_id":7,"item":"abc","name":"Keith","price":NumberDecimal("7.5"),"quantity":NumberInt("10"),"date":ISODate("2015-09-10T08:43:00Z")},{"_id":8,"item":"abc","name":"Michael","price":NumberDecimal("10"),"quantity":NumberInt("5"),"date":ISODate("2016-02-06T20:20:13Z")},]

db.collection.aggregate([{"$facet":{"groupByName":[{"$match":{"name":"Keith"}},{"$group":{"_id":"$name","count":{"$sum":1}}}],"groupByItem":[{"$match":{"item":"abc"}},{"$group":{"_id":"$item","count":{"$sum":1}}}]}}])