Sidebar with icons


I have a question about Sidebar. I found that when I click on a Tab the Sidebar appears. However I wish the same function but the difference of the Command/Icon. So is that possible if I click on an Command/Icon I get the sidebar appear or it works only with Toolbars? This way I could minimize the number of icons getting more space on screen and would be better organized.

Sidebars are only connected to toolbars.