During the initial phase of the Final Fantasy VII Remake, there is a tutorial part where it explains how locking onto targets works. If you missed these tutorials or forgot it, you come to the right place.
In this guide, you will learn how to locked targets or switching targets to multiple enemies in the PlayStation 4 system.
Locking Onto Targets
To lock on to the target, look to the target enemy and press the 
R3 button. This will show a blue box with X on the center identifying it is now in the locked mode.
To unlock the target, simply press the R3 button again to the free area.
Switch between Multiple Targets
If you have several enemies and want to switch targets, simply pressing the 
d-pad left and right button will automatically switch targets to its direction.
You can also use the R3 button to switch target, but you need to look for the target.
Note: The following guides are pulled from the leaked video footage of Final Fantasy VII Remake.