[{_id:1,name:"Person1",rating:50},{_id:2,name:"Person2",rating:55},{_id:3,name:"Person3",rating:60},{_id:4,name:"Person4",rating:65},{_id:5,name:"Person5",rating:70},{_id:6,name:"Person6",rating:75},{_id:7,name:"Person7",rating:800},{_id:8,name:"Person8",rating:850},{_id:9,name:"Person9",rating:900},{_id:10,name:"Person10",rating:100000},{_id:11,name:"Person11",rating:100001},{_id:12,name:"Person12",rating:102000}]

db.collection.aggregate([{"$setWindowFields":{"partitionBy":null,"sortBy":{"rating":1},"output":{nearDocs:{$addToSet:"$_id",window:{documents:[-3,3]}}}}},{"$sample":{"size":1}},{"$lookup":{"from":"collection","localField":"nearDocs","foreignField":"_id","as":"nearDocs"}},{"$unwind":"$nearDocs"},{$match:{$expr:{$ne:["$_id","$nearDocs._id"]}}},{"$sample":{"size":1}},{"$project":{matchPairs:[{_id:"_id",name:"$name",rating:"$rating"},"$nearDocs"]}},{"$unwind":"$matchPairs"},{"$replaceRoot":{"newRoot":"$matchPairs"}}])