Database
[{_id:1,level:"High",country:"Palestine"},{_id:2,level:"Low",country:"Jordan"},{_id:3,level:"High",country:"Jordan"}]
Query
db.collection.aggregate([{"$facet":{"groupByLevel":[{$group:{_id:"$level",count:{$sum:1}}}],"groupByCountry":[{$group:{_id:"$country",count:{$sum:1}}}]}}])