You're doing it the hard way.
Either click 'My Page' on the top menu and click on your boardmark for the desired destination; or...
click 'Forum Home' and find your destination among the Hot Boards there. (There are fewer than a dozen or so posters on all of AB and only a few boards active so they're always on the Hot Board list.)
Two clicks in either case. Easy.
Also, the dropdown box on the right should only contain your Boardmarks so mark your fave boards and you're again two clicks away.