I'm not one for crude language, so I'll use the polite abbreviation 'BS'. This usually means 'nonsense', particularly where someone is trying to deceive other people. For example, let's say one of your colleagues makes a mistake at work. When this person is questioned about their mistake, they might try to pretend that they hadn't done this, or they might invent an implausible story to justify their actions. If you don't believe what they are saying, you'd say that your colleague is talking BS - implausible nonsense which fools nobody. I suspect the word 'land' here means 'territory', in the sense of topic or direction of conversation. For example, someone might begin a story by telling the truth. However, as what the person is saying becomes ever more implausible (maybe lying, or boastful), you might say 'We're really in BS land now' to indicate your scepticism.

"Bullshit" is a term that is often used to describe something that is messed up or rubbish. So "Bullshit land" might be used to describe a country that someone doesn't like or thinks is rubbish. "I'm fed up with living in this bullshit land" It should be pointed out that "bullshit" is a profanity and can offend some (sensitive) people :-) It should only really be used in informal situations with friends. Hope this helps!