Let me add that while the examples from the website are okay, "been being here" doesn't work in your first example. The difference is in their example, it refers to spending time (not stative), but in yours it refers to being in a location (stative.)

Both of those examples are fine. There are some stative verbs that aren't normally used in the perfect simple tenses that can sometimes be used in the perfect continuous tenses. Two others that fit that description are "to want" and "to mean."

It is grammatical to follow "I have been" with ANY present or past participle. "Being" is not an exception. Your first sentence is most definitely not wrong. There are situations where "I've been being here for a while" would be superior to "I've been here for a while". "Been being" conveys a continuous presence that "been" does less well. Consider this example: A guard is sitting watch for intruders. His superior suspects that perhaps the guard has been taking naps or wandering off. The superior confronts the guard but the guard defends himself saying "I have been being here and doing nothing else for the last three hours". "Being" is not necessary but adds emphasis to the continuity of his presence. It also provides symmetry with "doing".

I would say that the reason the first one is incorrect is because saying "I've been being here" vs. "I've been here" doesn't add any more information about you being there and therefore sounds unnatural even though it might technically be grammatically correct. When you say "I have been here" it can be taken to mean that you've either been there until the moment that you've spoken or that you've been there in the past at some other time, i.e. "You've been there before". So, context is what differentiates those. You can say "I've been doing something or other" as long as what you're "doing" isn't "being". In your first example, "it's been being" isn't one verb phrase. The "being" is part of a gerund phrase which is why it sounds fine because it's acting as a noun. In your second example, it sounds fine, and I think a native speaker would use it, but if we're being nitpicky, it does sound a little off even though it's totally correct. It's different than the "I've been being here" because in this example, the sentence is in the passive voice, so we need the extra being to do that. I do think it would sound better if it wasn't in the passive voice but rather in the active voice instead, like, "He'd been abusing me..." rather than "I'd been being abused by him".

They’re correct. It has been a blast /working with you/skiing this slope/being here etc. /being abused/being wooed/being harassed/ being pursued/ etc. are objective and observable. You can express these ideas with other verbs though. E.g ‘I felt harassed. ‘ is more subjective than ‘I was being harassed’ but the meanings aren’t all that far apart. I’d also add that the structure ‘I’d been being..’ though correct sounds a bit jarring because it’s uncommon. Btw- I’ve learned that grammatically it is not … … these examples