One of my favorite tools in CorelDRAW is one that is virtually hidden. I guess that is only appropriate as it makes it easier to select hidden objects. If you look in the toolbox, you won’t find the Digger tool as it is nothing but a hidden function of the Pick tool.
Clicking on an object with the Pick tool will select it. But hold down the Alt key and you will select whatever is behind that object. If there are more objects stacked behind the selected object, just keep Alt + clicking until you have the desired object selected. I always keep my eye on the Status Bar to see what is selected, the fill and the outline until I have the object I wanted.