If you turn on Show Containers, you will see there are some widgets at the bottom of each post.

If you are the sole author, it's very easy: you can add a Free HTML widget and add anything you want.

Otherwise, we probably have the About Author Widget... but it seems it doesn't work all that well right now. We'll check quickly.

This widget actually works: http://b2evolution.net/man/about-author-widget

Okay, I am somewhat lost here.

If I wish to add the Widget: About Author and I would like to list the micro bio and another field, like the authors facebook link or telephone number, I assume I have to add the twice. See picture. The thing is, the second item shows up twice and the third three times... bug? am I using it wrong? Not that I can check on the demo site...