Hi Cervage, just use the New Business Object menu item from the same module.
Here's an excerpt from page 21 in the 4.5 Application Building user guide:
Copying business objects
If you create a new business object by clicking the New Business Object menu item, the new business
object is created with copies of the module’s base business object’s sections, fields, associations, and
state transitions. Sometimes, it is more convenient for the new business object to be copied from a
different business object.
You also can create a new business object by copying any non-base business object in a module. To do
this, view the properties of the existing business object you want to copy. When the business object’s
properties appear, a Copy BO action also appears at the top of the Data Modeler. Clicking the Copy BO
action causes a Name property to appear in the Data Modeler’s Property panel. Set the value of the
property to the name you want the new business object to have. Finish by clicking the Ok action at the top
of the Property panel.