TubeInitializer arranges cells in a cylinder shape. 
This demo shows that tubes can be laid out in any arbitrary orientation, and you can arrange layers of hollow tubes surrounding one another. 
In XML file, you can un-comment one TubeInitializer steppable at a time to build a tube along an axis specified by the <Extrude> parameter. 
While TubeInitializer is intended for 3D simulations, it is also possible to generate concentric circles of cells. Example 5 in the XML shows this. 

See the documentation for more details: https://compucell3dreferencemanual.readthedocs.io/en/latest/tube_initializer.html