Filter CloudWatch logs with a property selector for a JSON property containing a period character "." - amazon-cloudwatch

Question

How would I write a CloudWatch filter with a property selector for a JSON property containing a period character "."?
The CloudWatch documentation describes using a property selector to filter log data (https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/FilterAndPatternSyntax.html#metric-filters-extract-json):
Documentation Syntax:
{ PropertySelector EqualityOperator String }
Documentation Example:
{ $.eventType = "UpdateTrail" }
If a log event contains a JSON property containing a period character ".", is it possible to describe it with a property selector?
I have attempted the following property selectors:
Filter encounters error { $.attributes.http\.method = "POST" }
Filter encounters error { $.attributes["http.method"] = "POST" }
Filter produces zero results { $.attributes.http.method = "POST" }
Example Event
{
"traceId": "75e07edf6f50ddf0d4a8239cbe91d60a",
"parentId": "f8875623e2e77de4",
"name": "request handler - /subscriptions",
"id": "7f8b38dcbbb15983",
"kind": 0,
"timestamp": 1673621283065,
"duration": 3,
"attributes": {
"http.route": "/subscriptions",
"express.name": "/subscriptions",
"express.type": "request_handler",
"http.method": "POST",
"http.url": "/subscriptions",
"http.body": "{\"foo\":\"bar\"}"
},
"status": {
"code": 0
},
"events": [],
"links": []
}