Entity or Table Layering

When you work with multiple entities or tables, in order to maximize how many objects you can view, you may want to layer the objects on the diagram window. For example, if you want to view all of the entities that relate to the Accounting department, but you do not need to see the details, you can layer the entities.

You can also layer groups of model objects. For example, if you have two groups of entities, you can layer the groups in order to fit more on a page.

Other commands in the model can affect your customized settings. For example, if you automatically lay out your entire diagram window using the Layout option on the Diagram menu, all of the display settings for grouping, aligning, layering, or spacing objects will be overwritten.

More information:

Group Objects on the Diagram Window