You may want to create variations of an object in the same library. To do it, you need to copy the original object and paste it in a new object, and then modify.
To create an object variation in the same library
1.Open a library.
2.Double-click an object to open it in a new tab.
3.Select the object and then press CTRL+C to copy the object on the clipboard. Note: the Tool settings are copied too.
4.Right-click anywhere in the list of objects, and then select New.
5.In Object name, type the unique name for the new object, and then in Description, type the optional comment for the new object.
6.Click OK. This opens the new page tab with the space for the new object.
7.Press CTRL+V. The object is pasted in the object library editing window on the same position as it was in the original object page and it is exact duplicate. Modify it as will.
8.Save the changes and then close all open windows.