AcessDiff has the ability to compare two different objects within the same database.  Click the Compare Two Objects tab, choose the database path, the object type, object 1 and object 2; then click Compare.  In the example below two tables are compared Downloads and Downloads2. 

The Select Objects tab and the Object Options on the Advanced tab do not apply when comparing two objects in the same database.

AccessDiff supports password protected and security group protected databases when comparing two objects.  Simply click the Password Protected checkbox and enter in the user name and password.