Select an element on the 3D view, then on the 3D view control tiles, select Hide Selected to hide the selected element. Which has the effect of temporarily suspending any current multi-pick sequence and allows the obscuring element to be picked. Doing this causes the picked element to be hidden whereupon the multi-pick sequence are restored, which allows the user to complete the sequence.
Select an element from the displayed list and click Show Objects to display the selected element in the 3D View.