Selecting 'Express' in the Utility Panel area will display a panel of 15 'Express Buttons'. These buttons can be used to rapidly access different nodes on the Tree or  open frequently used documents for editing or viewing.

To populate the button with the desired action simply 'drag' the node from the Tree view and drop it onto the button of choice.

From that point if you click the button it will scroll and filter the Tree view to show you the source of this action and then it will execute the default action for that node. In most cases this will be to open the file associated with the node for editing performing any necessary Check-Out  to support that action.

Button actions may be change by repeating the drag/drop  process detailed above.