Allow easy whitelist of more than subdomain
Background
Most of the time I want to whitelist a page for adblock, I want to do the entire domain. The current user interface slider that will easily whitelist the page for you defaults to the exact subdomain. (The www subdomain is always ignored, but otherwise the default is to whitelist just the subdomain). I like having the number of whitelists small, and unless I have a good reason I'd rather whitelist the entire domain. e.g. google.com instead of 800 separate subdomains.google.com
Currently the way to do this is to accidentally use the slider, then undo that, then highlight and copy the domain name, go to settings, and manually add it to whitelist.
I do understand that restricting to a subdomain is an important and common use case so I would never recommend replacing the UI but instead supplanting it. (Imagine subdomains of tumblr.com where they're all partly run by different people)
What to change
Note that arbitrary depths of subdomains can exist. e.g. sub1.sub2.sub3.foo.com sub1.sub2.sub3.foo.co.uk
Whatever UI element handled this it would need to understand not to always just keep two levels (e.g. whitelisting co.uk is probably not intended).
Maybe this could be done with a couple of buttons near the whitelist slider, e.g. "be more restrictive/be less restrictive", to add/remove one level
e.g. if we're on app.pillpack.com the 'bigger domain' button would replace it with 'pillpack.com', smaller domain would add the 'pill' level back on.
I suppose it could work nearly as easily to simply have a text box there so you can edit what gets whitelisted. (Still saves a couple of steps).