Retrieve the key value by passing another key value in json

My Json looks like this 🙂
{ “main” :[
{
“CM”: “T”,
“TM”: “”
},
{
“CM”: “100000”,
“TM”: “9999”
},
{
“CM”: “200000”,
“TM”: “”
} ]
}
This is stored in an test.expr file.

I have the CM values coming from the previous snap. What i would like to achieve is - I would like to pass 100000 to CM and retrieve 9999 as result.

How can I achieve this ?