[{_id:1,personId:"Sai",pnr:"P1",flight:"F1",hotel:"H1"},{_id:2,personId:"Sai",pnr:"P2",flight:"F2",hotel:"H2"},{_id:3,personId:"Sai",pnr:"P3",flight:"F3",hotel:"H3"},{_id:4,personId:"Sai",pnr:"P4",flight:"F4",hotel:"H4"},{_id:5,personId:"Sai",pnr:"P5",flight:"F5",hotel:"H5"},{_id:6,personId:"PJ",pnr:"P1",flight:"F1",hotel:"H2"},{_id:7,personId:"PJ",pnr:"P2",flight:"F1",hotel:"H3"},{_id:8,personId:"Kumar",pnr:"P6",flight:"F6",hotel:"H1"},{_id:9,personId:"Kumar",pnr:"P7",flight:"F7",hotel:"H1"},{_id:10,personId:"Kumar",pnr:"P8",flight:"F8",hotel:"H1"},{_id:11,personId:"Kumar",pnr:"P9",flight:"F9",hotel:"H1"},{_id:12,personId:"Kannan",pnr:"P10",flight:"F10",hotel:"H1"},{_id:13,personId:"Kannan",pnr:"P11",flight:"F11",hotel:"H6"},{_id:14,personId:"Akansha",pnr:"P12",flight:"F12",hotel:"H6"},{_id:15,personId:"Akansha",pnr:"P13",flight:"F13",hotel:"H7"}]

db.collection.aggregate([{$group:{_id:"$personId",personId:{$min:"$personId"},hotels:{$push:"$hotel"}}},{$match:{personId:{$ne:"Sai"}}},{$lookup:{from:"collection",let:{personId:"$personId",hotel:"$hotels"},as:"hotel_connections",pipeline:[{$match:{$expr:{$and:[{$in:["$hotel","$$hotel"]},{$ne:["H1","$hotel"]},{$ne:["$personId","$$personId"]},{$ne:["Sai","$personId"]}],}}},{$group:{_id:"$personId",hotel:{$min:"$hotel"},personId:{$min:"$personId"}}}]}},{$match:{hotels:{$in:["H1"]},hotel_connections:{$ne:[]}}}])