Define Integration Query string parameters with API GW HTTP proxy integration

I have a use case to use authorizer lambda and set parameters from Lambda (ex. from context) to Integration request’s query parameters for HTTP proxy integration (Calling HTTP endpoint written in Java). I know this is bit advanced use-case, can these type of use case define in serverless.yml? for the moment API GW configs are done manually, would like to get this automated with serverless.
I did not find any example of a post explaining the use case, Please let me know if you aware of any as well.