They changed the entire thing. I'm still trying to figure it out myself.

Are you using the Kindle App? I touch the middle top, then the header appears, with the title, etc. Then on the left side are the three lines, touch those and the menu appears for Library, Chapters, etc.

Yes, I use the Kindle app on the IPad. I have found the sorting on the right side now. Someone else suggested to clear the cache and reset which I did and it seemed to work for a moment better but then again, not. I am tapping the upper left of the screen several times and eventually, the three bars appear and I can tap and go where I want. Will try the middle tonight and see where that leads me.