[{_id:"a",points:1},{_id:"b",points:2},{_id:"c",points:7},{_id:"d",points:6},{_id:"e",points:38},{_id:"f",points:19},{_id:"g",points:254},{_id:"h",points:934},{_id:"i",points:45},{_id:"j",points:12},{_id:"k",points:8},{_id:"l",points:25435},{_id:"m",points:24}]

db.collection.aggregate([{$setWindowFields:{sortBy:{points:-1},output:{neighbors:{$push:"$$ROOT",window:{documents:[-3,3]}}}}},{$match:{_id:"k"}},{$project:{neighbors:1,_id:0}},{$unwind:{path:"$neighbors",includeArrayIndex:"index"}},{$project:{_id:"$neighbors._id",points:"$neighbors.points",index:1}}])