Context: 'I will be going tomorrow' and 'I will have been going tomorrow'. As meaning of both seems to be same, so what's the exact difference between the meanings of these two sentences?
If you want to indicate the duration of an event at a specific time in the future, you can use the future perfect progressive. This event will happen before a particular time in the future, yet hasn't happened yet.
By the time the season ends, I will have been playing for fifteen months.
If you are referring to an event that will happen before a specific time in the future, you can use the future perfect.
By tomorrow, I will have gone home.
If you are sure that something will happen because arrangements have been made you can use the future progressive.
I'll be going home tomorrow.
The difference is one of perspective, or temporal focus. I will be is looking forward from now to the event in the future. I will have been is looking backward at the event in the future from a point even further in the future.
Your example sentences don't make the difference clear.
I will be going to the university dental clinic tonight.
After tonight's visit, I will have been to the student dentist five times for this one tooth. Next time, I might go to a dentist who is already licensed and practicing.