You need "loop" input to make it in internal channels list
ex:
DVB-T > tvh > playlist output (normal output 1080p)
http://127.0.0.1:9981/stream/channelid/1391852216?profile=pass
then playlist
automatic playlist of upper channel but with profle (720/480)
file:///some/locatiom/playlist.m3u
#EXTM3U
#EXTINF:-1 logo="http://some.png" tvg-id="b8faf5d220e99e67a2e900bb88d4d63e",Channel 720p
http://127.0.0.1:9981/stream/channelid/1391852216?profile=720p
#EXTINF:-1 logo="http://some.png" tvg-id="b8faf5d220e99e67a2e900bb88d4d63e",Channel 480p
http://127.0.0.1:9981/stream/channelid/1391852216?profile=480p
Also possible to use Spawn profile and direct HLS output but will lose on-demand option.