So these probably won't work with Hubitat as-is; it's likely they use group broadcasting only or something that Hubitat doesn't support. A couple other Ikea products are like this, so it's not surprising. I'm guessing here, but if you have a ZLL bulb paired to Hubitat and want the motion sensor to control it in a semi-"dumb" fashion, you could probably still do that by linking the sensor to the bulb using Ikea's instructions (I think holding them near and holding the button on the sensor for about 10 seconds or until the bulb stops blinking) after having both paired to Hubitat. You'll lose any of Hubitat's ability to make it "smart" since you still won't see or be able to use it in Hubitat, but you can still use it with a Hubitat bulb that way--and the Ikea sensor has a few built-in options like timeout and light sensitivity (probably due to limitations of their own system), so you at least get some configuration.
These are not officially supported, either, so they are certainly not what Hubitat staff would recommend. 
That being said, many community members have been able to make them work. There is a large thread here dedicated to what you need to know to pair and keep them connected (Xiaomi & Aqara Devices - Pairing & Keeping them connected), but most of it is summarized in the first post and boils down to: be careful what Zigbee repeaters you use.
