Apply material to objects behind a front object

What is the easiest way to apply materials to objects that are behind or inside other objects?
Is there a simple way to hide the front object? I have been looking at Attribute editor, but not sure how to hide a selected object? Thanks

In the RenderView select the object you want to hide, the go to Edit -> Hide (or press Ctrl+H)
To unhide, go to Edit->Unhide All (or press Ctrl+Shift+H)

Thanks, That works great, :astonished: