This is a routine application for the Optosplit as the product has had provision for corrector lenses in one or other pathway since its inception.  This facility was originally provided for correction of any chromatic aberration in the preceding optics but rapidly found a further application for deliberately defocusing one or other imaging pathway in order to allow different depths to be in focus at the same time!  Obviously for z plane splitting a beam splitter is used rather than a dichroic. 
You may also be interested in our optosplit III which allows three different depths!