This is actually a bit of a misnomer at the moment, we need to update our messaging - but you can in fact restrict any websites you want.

To do it, open clearspace and tap one of the apps you've already set up. Then click the "websites" section. You'll be able to associate domains there, so whenever that app is unlocked, those websites will be as well. Otherwise they're restricted.

Hope this helps! Literally just rolling out website support so need to update the messaging in a few places, thanks for flagging.