Cycling playlists with one button: can I feed Media Player Source an Input Select..?

Configuration
1

I’m probably assuming this is easier than it is… Is it possible to just feed an input_select list to the media player service as a variable…?

Something like:

alias: Test Playlist Cycle
description: ''
trigger:
  - platform: state
    entity_id: switch.button
    to: 'on'
condition: []
action:
  - service: media_player.select_source
    data:
      source: !input_select.playlist_options
    target:
      device_id: 877b36f1019b11eba0204b2ba42127d9
  - service: input_select.select_next
    target:
      entity_id: input_select.playlist_options
mode: single

(which doesn’t work…)

TIA!

2 
action:
  - service: media_player.select_source
    data:
      source: "{{ states('input_select.playlist_options') }}"

See: Templating