Mongodb Find for Retrieving the Closest Larger / Closest Smaller Values from a List when there is No Exact Match?

db.js

var mongoose = require('mongoose')
    , Schema = mongoose.Schema;


var CloudSchema = new Schema({
    'Cloud_Provider' : {type : String, required : true, trim: true},
    'Lat' : {type: Number, required : true},
    'Long' : {type: Number, required : true},
    'Server_Type' : {type : String, required : true, trim: true},
    'Memory' : {type : Number, required : true, trim: true},
    'Storage' : {type : Number, required : true, trim: true},
    'CPU' : {type : Number, required : true, trim: true},
    'Region' : {type : String, required : true, trim: true},
    'Linux_Price' : {type : Number, required : true, trim: true},
    'Windows_Price' : {type : Number, required : true, trim: true}
});

var Cloud = mongoose.model('Cloud', CloudSchema);

exports.new = function(req, res) {
    cloud = Cloud(req.body);
    cloud.save(function(err) {
        if(err) {
            res.send({'code': 400, 'error': 'Some issue'}, 400);
        } else {
            res.send(cloud);
        }
    })
}

exports.search = function(req,res){
    var platform = req.query.plat;
    var memory = req.query.mem;
    var storage = req.query.strg;
    var cpu = req.query.cpu;
        Cloud.find({CPU : { $gt: cpu-2, $lt: cpu+2 } ,Memory : { $gt: memory-1, $lt: memory+1 },
                   Storage : { $gt: storage-50, $lt: storage+50 }}               
        , function(err, result){
        if(err) {
            res.send({'code': 400, 'error': 'Some issue'}, 400)
        } else {
            res.send(result);         
        }
    });
}

line 36 need a perfect query that would return Closest Larger / Closest Smaller Values from a List when there is No Exact Match