I'm wanting to create a sliding tool, similar to that in iOS where you adjust the brightness in the control centre.
Is this possible in XD?
any help out there?
Just as a heads up, the XD team generally doesn't work weekends (most of us are on PST/-8GMT), so you can expect a delay if you post on a weekend. Anyway, to respond to your issue: there's currently no way to make that type of interaction, though you might want to post that to https://adobexd.uservoice.com as a feature request. The best you'll be able to do at the moment is fake it through a dissolve transition.
Hope that helps!