I seem not to be able to position a couple of mail folders permanently at the top of the column of mail boxes

On MacOS Catalina there was the option to put a couple of mail box designations at the top of the list of mail boxes. I had my preferred inbox and my sent mail box there so I could click on one of those and the message list for that mailbox would show. Then, if I needed to open that mail box (or any mail box) to see its contents, I could do so. Then to get back to open the inbox again I merely have to click on the inbox designation at the top of the column and it would open and I could file the message straightaway into the mailbox that I had previously opened - it would be right there.

In MacOS Big Sur, there is no option to have such a fixed mailbox at the top and it means a lot of scrolling back and forth in the list of mailboxes from the inbox to another box and back to the inbox. This is MUCH less efficient and I really think it was not a good idea (dumb) to remove that nice feature I used all the time in MacOS Catalina.

OR, is that still an option in Big Sur and I have just missed it?