The binding changed in openHAB 3.3 Stable to using BRIDGE and children THINGs. You appear to only be looking at the channels for the BRIDGE indicated by the GLOBAL BRIGHTNESS channel. For each of your segments you need to have a THING that is linked back to your BRIDGE thing and each of the segment “THINGS” will have the channel you are after.
@fals3illusion
The documentation you provided the link for, does list the channels for the BRIDGE separately to the segment THING. Please check it out as it should clear it up as to what you should see.
Off the top of my head I do not believe there was any changes to the channels, but a fix was added for preset selections since the version in this thread. The info in this thread may be useful especially if you do textual config.