Issue while adding multiple filters in Grafana Mongo DB metrics

Hi All,

we have created a GRAFNA dashboard with Mongodb as data source. We are using below metrics query to get desired result and we able to fetch the right expected output.

db.perf_results.aggregate([
    { "$match" :    {    **"Bounded Context Name"  :  "$context"**, "timeStamp" : { "$gte" : "$from", "$lte" : "$to" } }  },
    {"$project" :   {  "name" : "$Bounded Context Name",   "value" : "$# Samples",  "ts" : "$timeStamp",  "_id" : 0} }
])

However when we tried to add another filter by creating additional variable it is not fetching us anything, am i missing something in the process or is there any other way to add filter . I am using below query to add multiple filter

db.perf_results.aggregate([
    { "$match" :    {    **"Bounded Context Name"  :  "$context",   "Label"  :  "$transaction",**   "timeStamp" : { "$gte" : "$from", "$lte" : "$to" } }  },
    {"$project" :   {  "name" : "$Bounded Context Name",   "value" : "$# Samples",  "ts" : "$timeStamp",  "_id" : 0} }
])

Regards,
Anuj