在支持多个BrightnessController接口实例的Alexa智能家居技能中，需要对每个BrightnessController实例提供唯一的标识符。以下是一个包含多个BrightnessController接口实例的示例代码：

{
  "endpointId": "light1",
  "friendlyName": "Bedroom Light",
  "description": "Smart light in the bedroom",
  "manufacturerName": "Smart Home Co.",
  "displayCategories": ["LIGHT"],
  "cookie": {},
  "capabilities": [
    {
      "type": "AlexaInterface",
      "interface": "Alexa",
      "version": "3"
    },
    {
      "type": "AlexaInterface",
      "interface": "Alexa.BrightnessController",
      "version": "3",
      "properties": {
        "supported": [
          {
            "name": "brightness"
          }
        ],
        "retrievable": true
      },
      "instance": "light1-brightnesscontrol"
    },
    {
      "type": "AlexaInterface",
      "interface": "Alexa.BrightnessController",
      "version": "3",
      "properties": {
        "supported": [
          {
            "name": "brightness"
          }
        ],
        "retrievable": true
      },
      "instance": "light1-secondbrightnesscontrol"
    },
  ],
  "connections": [
    {
      "type": "TCP_IP",
      "macAddress": "00:11:22:33:44:55",
      "address": "192.168.1.42",
      "port": 1234
    }
  ]
}

在此示例代码中，我们为每个BrightnessController接口实例提供了唯一的标识符。第一个BrightnessController实例的标识符为“light1-brightnesscontrol”，第二个BrightnessController实例的标识符为“light1-secondbrightnesscontrol”。Alexa将使用这些标识符来识别用户所请求的确切BrightnessController实例，并将相关操作路由到正确的实例。

请注意，我们还在每个BrightnessController接口实例中指定了可访问性和支持的属性。这些字段可以根据您的要求进行调整，以指定每个实例可以执行哪些操作，以及这些操作的可重复性。

使用此示例代码，您可以轻松地为支持多个BrightnessController接口实例的Alexa智能家居技