You can create a multi-column layout by nesting two vertical panes, side-by-side, within a horizontal parent pane.
Procedure
Place groups of controls into two separate vertical panes, each representing a separate column.
Drag the second pane to a position next to the first pane, so that you see a dotted line appear. The dotted line means that a horizontal pane will be automatically created for you to hold the two vertical panes.
As you drag the pane, you will see feedback on the new position of the pane prior to releasing the mouse button.
If you want more than two vertical columns, drag additional panes, one at a time, next to the right-most vertical pane within the new horizontal parent pane.
