Swagger Editor multiple parameters in body

I'm not sure to understand your question...

• If you are trying to define more than one body parameter for one operation, you can't. As explained in swagger specification:

Body [...] there can only be one body parameter

• If you are trying to send a body with multiple parameters, add an object model in the definitions section and refer it in your body parameter, see below (works with editor.swagger.io):

Your example nodes also are wrong, see here for more details.

swagger: '2.0'
info:
  version: "0.0.1"
  title: Todo App
host: localhost:3000
schemes:
  - http
  - https
consumes:
  - application/json
produces:
  - application/x-www-form-urlencoded
basePath: /
paths:
  # This is a path endpoint. Change it.
  /tasks:
    post:
      description: |
        Add 'Task' object.
      parameters:
        - name: task 
          in: body
          description: task object
          required: true
          schema:
            $ref: '#/definitions/Task'
      responses:
        200:
          description: Successful response
          schema:
              title: Return String
              type: string
              example: "Task added succesfully"
        500:
          description: Error
          schema: 
            type: string
            example: "Could not add Task"
definitions:
  Task:
    description: Task object
    properties:
      name:
        type: string
        description: task object name
      description:
        type: string
        description: task description
    required:
      - name
      - description

You can also define the properties of the request body parameter using properties as part of its schema. This has a good example under Object Payload: https://swagger.io/docs/specification/2-0/describing-request-body/.

paths:
  /users:
    post:
      summary: Creates a new user.
      consumes:
        - application/json
      parameters:
        - in: body
          name: user
          description: The user to create.
          schema:
            type: object
            required:
              - userName
            properties:
              userName:
                type: string
              firstName:
                type: string
              lastName:
                type: string
      responses:
        201:
          description: Created

The disadvantage of course is that you don't get the reuse of an object definition, but sometimes an object definition isn't appropriate.