"Ah, ok. Now again, you did not narrow what you intended by this scope, so I will do my best to address what you think the problem is based on the old Nagel paper.
Nagel's point is not incompatible with mine. Nagel is trying to note that one's personal experience is something that no one will ever be able to have identically. We can't post a picture on the wall for example of what you see before you, and it be the exact picture you experience personally. But what we CAN do, is measure your brain activity, and find brain activity that matches the personal experience you are having.
Yes, we have found lots of neural correlates to consciousness. Chalmers calls that the "easy problem". The Hard Problem is WHY are we conscious AT ALL and HOW does consciousness arise from non-conscious stuff? Science's failure to explain those key questions is called the "explanatory gap".
Understand that Nagel wrote this paper almost half a century ago, and such advances did not exist. It wasn't on his radar, or the scope of his topic. While yes, nothing will ever duplicate the experience you are having, that does not mean we cannot find the underlying physical processes that are causing you to have that personal experience. Modern neuroscience is at that step. I cited two papers which show this.
Yes, you're talking about neural correlates. Correlation is not causation. Suppose science found the exact two million neurons associated with first person subjective experience. That would still put us no closer to answering the Hard Problem.
The first is the ability to read a person's mind and match it with a number the person is thinking of. When the person thinks, "10" we do not know the tonality they are speaking in (yet, we may in the future). But that is irrelevant. We know they are thinking the number "10", and are then able to represent this through a voice synthesizer. We have evidence now that the thoughts we have are able to be matched to the brain's physical process.
Again, suppose we invent a machine that exactly tells us what another person is thinking about. We still haven't solved the Hard Problem.
The second paper is the advances in consciousness. Consider for a minute that your conscious mind does not have control of your entire body. You cannot tell your gall bladder to produce more or less gall for example. There are certain areas of your brain you do not have access to. The brain has independent sections that manage certain tasks like sight, sound, and language. We know this because we have found damage or stimulation to these regions also affects people's personal experience in these areas. All of these areas need to be combined together into something coherent to be able to make basic judgments. It is worthless to see if it does not help you identify food from not food within that sight for example.
That's true, but doesn't address the Hard Problem.
Consciousness is the cobbling together of certain resources to make decisions.
Look up "philosophical zombie" (again, Chalmers).
Should I pursue that food, or should I not. With intelligence comes a greater ability to make judgements, and manage the different resources of the brain. All of this, is the brain itself. Philosophy is not about creating arguments based on ignorance. It is about creating arguments about things we are ignorant to, while basing it upon our limitations of the reality we know. If you wish to do viable philosophy in regards to the mind, old arguments that do not address modern day findings of neuroscience will be an argument based off of ignorance, and not very useful. Perhaps you will present me with a philosophy theory about the mind that neuroscience cannot be helpful in and prove me wrong.
You should also read about Integrated Information Theory. I think you might find it interesting.