Hi,

You would want the focus target bar.

Only available on PC currently
http://na.finalfantasyxiv.com/lodest...uide/win/view/

In addition to your current target, you can also keep an eye on other enemies or allies by making them focus targets. This is a good way to keep track of one target’s HP while dealing with another. A focus target can be designated by clicking on the target and pressing Shift+F. You can switch your main target to the focus target by clicking on the focus target bar.

Hopefully they will review it for the PS3.