Select multiple entities to link their on/off state. If any selected entity is turned on or off, the other selected entities will be sent a matching on or off command.

link_multiple_devices.yaml

blueprint:
  name: Link On/Off State of Multiple Devices
  description: |
    ## Link On/Off State of Multiple Devices v1.0.0

    Select multiple entities to link their on/off state.  If any selected entity is turned on or off, the other selected entities will be sent a matching on or off command.

    You can select any entity, but only entities supported by the `homeassistant.turn_on` or `homeassistant.turn_off` service calls will work.

    This blueprint allows you to select multiple groups of entities, to combine the link automations into one

    ### Requirements
    * All selected entities MUST suport `homeassistant.turn_on` and `homeassistant.turn_off` or errors will be logged and the blueprint will not work.
    * Requires Home Assistant 2022.5.0 or newer.
    
    ### Credits
    * [@adchevrier](https://community.home-assistant.io/u/adchevrier) for the [initial blueprint](https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010)
    * [@hebus](https://community.home-assistant.io/u/hebus) for [this fantastic template](https://community.home-assistant.io/t/synchronize-the-on-off-state-of-2-entities/259010/38)
    * [@luma](https://community.home-assistant.io/u/luma) for [the updated blueprint](https://community.home-assistant.io/t/link-on-off-state-of-multiple-devices/460310)
  
  domain: automation
  homeassistant:
    min_version: 2022.5.0
  input:
    linked_entities_1:
      name: Entities to link 1
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_2:
      name: Entities to link 2
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_3:
      name: Entities to link 3
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_4:
      name: Entities to link 4
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_5:
      name: Entities to link 5
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_6:
      name: Entities to link 6
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_7:
      name: Entities to link 7
      default: {}
      selector:
        entity:
          multiple: true
    linked_entities_8:
      name: Entities to link 8
      default: {}
      selector:
        entity:
          multiple: true

mode: restart
max_exceeded: silent

variables:
  linked_entities_1: !input 'linked_entities_1'
  linked_entities_2: !input 'linked_entities_2'
  linked_entities_3: !input 'linked_entities_3'
  linked_entities_4: !input 'linked_entities_4'
  linked_entities_5: !input 'linked_entities_5'
  linked_entities_6: !input 'linked_entities_6'
  linked_entities_7: !input 'linked_entities_7'
  linked_entities_8: !input 'linked_entities_8'

trigger:
- platform: state
  entity_id: !input 'linked_entities_1'
  id: trigger_1
- platform: state
  entity_id: !input 'linked_entities_2'
  id: trigger_2
- platform: state
  entity_id: !input 'linked_entities_3'
  id: trigger_3
- platform: state
  entity_id: !input 'linked_entities_4'
  id: trigger_4
- platform: state
  entity_id: !input 'linked_entities_5'
  id: trigger_5
- platform: state
  entity_id: !input 'linked_entities_6'
  id: trigger_6
- platform: state
  entity_id: !input 'linked_entities_7'
  id: trigger_7
- platform: state
  entity_id: !input 'linked_entities_8'
  id: trigger_8

action:
- choose:
    - conditions:
        - condition: trigger
          id: trigger_1
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_1) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_2
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_2) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_3
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_3) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_4
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_4) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_5
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_5) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_6
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_6) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_7
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_7) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'
    - conditions:
        - condition: trigger
          id: trigger_8
        - condition: template
          value_template: '{{ trigger.to_state.state != trigger.from_state.state }}'
        - condition: template
          value_template: '{{ (trigger.to_state.state == "on") or (trigger.to_state.state == "off") }}'
        - condition: template
          value_template: '{{trigger.to_state.context.parent_id is none or (trigger.to_state.context.id != this.context.id and trigger.to_state.context.parent_id != this.context.id) }}'
      sequence:
        - service: homeassistant.turn_{{ trigger.to_state.state }}
          target:
            entity_id: '{{ expand(linked_entities_8) | selectattr("entity_id", "!=", trigger.entity_id) | map(attribute="entity_id") | list }}'