I would do this

1. parse to custom object
2. do a For-loop by the required property
3. break the loop as soon I found the match

Considering your object variable is named someObject, you can access it like:

var comLength = someObject["some-key"].comLength

Example:

var someObject = {
     "Key": "some-key",
     "some-key": {
        "comLength": 1
     },
}

var comLength = someObject["some-key"].comLength;

console.log(comLength);

You can reference it via the dot notation (.) and the square notation ([]) (the [] notation is mandatory in case of the property key of some-key because of the -)

const obj = {
    "Key": "some-key",
    "some-key": {
            "comLength": 1
        }
};


console.log(obj["some-key"].comLength);
console.log(obj["some-key"]["comLength"]);