With the buttons on the left-hand side (Overview, Account, Checkouts & Requests, Bills & Fines, Bookmarks, Saved Searches), some of them do not provide easy navigation back to the start once you are within that area. For example, I click on Bookmarks and it takes me to the list of my lists. But if I then click into one of the lists, clicking that button doesn't take me back out to all my lists. There is a breadcrumb navigation trail at the top, which is good, but I would also expect the button on the side to take me back to the top of the area.

Similarly, when in Hold Requests or History, I would expect the Checkouts & Requests button to take me back to the default view, Checked Out.

I was told this is an idea not a bug, so it seems easy to implement with enough votes!