如何在serverless.yaml中引用自定义块中的条件变量

functions:
  myFunction:
    handler: handler.myFunction
    environment:
      MY_VARIABLE: ${self:custom.variableName}

resources:
  Resources:
    myTable:
      Type: AWS::DynamoDB::Table
      Properties:
        TableName: ${self:custom.variableName}
        ...

functions:
  myFunction:
    handler: handler.myFunction
    events:
      - http:
          path: myPath
          method: get
          integration: lambda
          request:
            parameters:
              querystrings:
                myParam: ${self:custom.variableName}