To open the DoBeSphere tool, double-click on "DoBeSphere" in the Toolbox.
To understand how DoBeSphere operates, imagine a "virtual sphere" that is centered at the location you designate with the tools Origin Tab, sized to just surround all of the currently selected points. When you alter the X, Y, Z Mapping Factor values, the currently selected points will be moved "inward" or "outward" along each of the axes towards the surface of the virtual sphere. For example, consider the following object, and assume that "Geometric Center" is set on DoBeSpheres Origin Tab:
With X, Y and Z Mapping Factor all set to "0.5", the object is moved halfway between its current shape and the shape of the virtual sphere surrounding it:
With X, Y and Z Mapping Factor all set to "1.0", the object has now assumed the shape of a complete sphere:
With DoBeSpheres Origin Tab set to "Min Y", the object is still conformed to the surface of a sphere, but the sphere itself is now centered around the objects minimum Y coordinate. The sphere size is still calculated to just enclose the object, so the sphere has grown:
Note that you can also use DoBeSphere interactively, LMB Dragging to alter the Mapping Factors of the two axes that arent Active; or, you can hold down either control-key and LMB Drag to alter the Mapping Factor of the current Active Axis. Finally, you can hold down either shift-key and LMB Drag to alter all three Mapping Factors at once.