Purpose for command Audit Role 2 drop down in iCommand

hi

What is the use of command Audit Role 2 ?

For Example

i configured iCommand Applet with Command Audit Role 1 and command Audit Role 2 for some data base operation.

SAP xMII security manager asking Audit Role 1 credentials and then Audit Role 2 Credentials when executing the data base operation.In real time Audit Role 1 will play first user(operator) and Audit Role 2 will play second user(superwiser).SAP xMII asking Audit Role 1 and Audit Role 2 credentials in continously for first user itself.

why it's asking command Audit Role 2 also to first user itself.how to first user know about second user credentials?