Rename returned variable from intent from sonos_favorites

Configuration Voice Assistant
1

I have a custom intent to play a Sonos Favorite on a selected sonos speaker. Works fine. Here are the relevant parts:

entity sonos_favorites has these attributes

items: 
FV:2/23: RP Main Mix
FV:2/22: RP Mellow Mix

My working custom sentence

language: "en"
intents:
  PlayMusic:
    data:
      - sentences:
          - "Play {source} (on|in) [the] {media_player}"

lists:
  source:
    values:
      - in: "mellow"
        out: "FV:2/22" # I hard coded this infrom sonos_favorites
      - in: "main"
        out: "FV:2/23"
      - in: "world"
        out: "FV:2/20"
  media_player:
    values:
      - in: "(living room)"
        out: "media_player.living_room"

My working custom intent_script

 # Media
  PlayMusic:
    action:
      service: "media_player.play_media"
      target:
        entity_id: "{{ media_player }}"
      data:
        media_content_type: favorite_item_id
        media_content_id: "{{ source }}"
    speech:
      text: |-
        "OK, playing {{ source }} on {{ state_attr(media_player, 'friendly_name') }}"

When I say “play mellow in study” the response is “OK, playing FV:2/22 on study” and it plays the correct favorite. Good.

BUT
I want it to display/say “OK, playing RP Mellow on study” which is the sonos_favorites name for value FV:2/22

So

  1. how do I either set the intent list out to “RP Mellow” from the sonos_favorites array I have looked at the sonos examples and had no luck getting the name from the value
    OR
  2. Once “FV:2/22” is sent/passed to the intent script how do i template/translate it into “RP Mellow” with an if statement

I have tried to get the name vs the value of of the sonos_favorites array with no look and I have tried templateing the iintent_script with no luck as well.

thanks