Hubitat's Hue Bridge integration exposes only bulbs (and groups and other lights), not "sensor" devices, including accessories like the Tap and Dimmer (and motion sensor). The reason, presumably, is that this would not be very useful: the only way Hubitat has to access these devices is polling/refreshing states over the HTTP API, not "pushing" from Hue to Hubitat, so there would be a delay before these events become usable to Hubitat but this would limit their usefulness for most people there.
The Dimmer can be paired directly to Hubitat, and an app like Advanced Button Controller or Dimmer Button Controller can be used to cycle through scenes with multiple button presses, emulated in software on Hubitat (and presumably Hue). Unfortunately, you have to go a bit slower with the presses on Hubitat since it all goes through the Hub; on Hue, you can just mash the button five times quickly to get to the fifth scene, but Hubitat (and whatever scenes or lights you are controlling) will likely need some time to recover after each press (less than a second in my experience but still no repeated mashing) to get where you want. Also unfortunately, some people have had trouble keeping these paired; it may depend on what channel you're on (presumably the ZLL ones should work without issue), device firmware, or just luck.
If you're opposed to custom apps (though I think Advanced Button Controller is great and I haven't heard of any problems), you could do the same with Rule Machine and a "Button Device" trigger (I wouldn't use the regular Button Controller app for this, but RM with this trigger is nearly the same, except it gives you the power of RM like variables you can use to track button press numbers).
