When you book a ticket on the EK site, it will ( from what I can tell ) try and find a through fare that meets that journey
If you are travelling to a place to which EK publishes a fare, then all fine, but if trying to book a fare to a destination where it doesn't, then it will often just take a full fare to that destination rather than piece together fares
Where are you trying to get to? EK seems to be adding additional destinations within Australia that they sell tickets to, but some seem to have no business/1st offerings