I'm not sure why you would ever want to do that.
If it is to display two different sets of available reports to two different audiences then this is not the correct way to go about it. you should permission the reports available based on the two user groups using whatever authorization approach you have chosen - NTFS file permissions, AD, LDAP...?
Also I guess it could be because you want to have two different authentication methods for your split audience.
Can you provide more information as to what your aim is?