How to create two database copies in two users from same dump file
If your dump has been created with exp then you may use imp for importing it. If you exported schema USERA and want to import these objects in schema USERB, then use command:

imp user/password@sid FROMUSER=USERA TOUSER=USERB FILE=yourfile.dmp


you may get more example of imp on the Import Export FAQ. You may import your dump two times using different USERB.