How to achive this is node Js/Express with Redis ? basically storing a call back value to a variable

My data structure is like below in redis. I want to get all the value in list and it's relavent data from other sets.

Data structure :

lpush mylist test1
lpush mylist test2
lpush mylist test3

set test1 "test1 value1"
set test1 "test1 value2"
set test2 "test2 value1"
set test2 "test2 value2"

I want to get all values from list and relevant set values.

I tried like this below.

var redis        = require('redis')
var redis_client = redis.createClient();


var test = redis_client.lrange(conv_id, 0, -1, function (error, response) {
                     return response;
             });

var datas = redis_client.mget(test, function (error, response) {
                     res.send("datas_text", {data: response});
             });

How to get the callback value ?

But this way it is working.

 redis_client.lrange(conv_id, 0, -1, function (error, response) {
                   redis_client.mget(response, function (err, datas) {
                      res.send("datas_text", {data: datas});
                   });
             });