Summary
This is a simple design for a parametric lasercut desktop filing rack in OpenSCAD.
Open the design in OpenSCAD, enter your parameter set and export as DXF. The DXF contains the outlines for the three different parts of the design: the back panel, the sides and the shelves. Cut them as often as needed and then glue the parts together.
The example parameter set generates a design that is good for A4 papers and 6mm material thickness.