Blocks either everything or nothing

My website doesn’t use posts – there are no posts – and nearly everything is either on woocommerce or buddypress – if I try to select any specific “page” to block (all of my pages are rendered dynamically by woocommerce or buddypress) it either blocks the entire site, or nothing at all. I’d like to keep the public URLs available and only the members area, buddypress/woocommerce/etc proxyblocked, but I’m not sure how to achieve this unless there is some sort of code that I can manually place in functions – using your page selector is ineffective