How to momentarily exit a book in Apple books?

miss the line at the bottom of the page which used to let you know in a glance your progress on the particular book you're currently reading. (I can live without it, but I don't like not having it.) But a major problem I discovered this morning is that if you're in the middle of your book and you'd like to exit it momentarily to see your list of books or to buy a new one, it's impossible to exit the book! Is there any way around this (to me) major issue? or is there a way to go back to the old version of Apple Books? I ABSOLUTELY HATE THE NEW VERSION!

[Re-Titled by Moderator]