I mostly have Now TV for HBO content, and when I had the app on my Apple TV 3rd Gen a few years ago I remember being able to view all their content on a single page.
Now I'm using a Mac and I can't seem to be able to find that option. I can view by channel, and get a lot of HBO results from viewing the Sky Atlantic and Sky Comedy channels. But I'm looking for a way to view all the HBO shows on the same page.
I used to have an Apple TV gen 3 box and i can't remember ever seeing a dedicated section purely for All HBO content in the NOW library (apart from something like this on the screen shot below for popular HBO TV shows).