Configure include paths
Include paths are used for holding libraries, that is, third-party code that is used for completion and reference resolution in some functions/methods that use file paths as arguments, for example, require() or include().
Note that the files added via include paths are not meant to be edited within the scope of your project. If you have the existing code that you need to access and modify from within several projects, consider adding it via an additional content root.
Configure include paths
In the Settings dialog (Ctrl+Alt+S) , click PHP.
On the PHP page that opens, configure the list of library folders on the Include path tab:
Use
and 
to add and remove folder paths.Select a folder and click
Exclude to exclude the contents of this folder from indexing.
Configure include paths for all newly created projects
To configure include paths that will be applied to all newly created projects, use the default new project settings:
In the main menu, go to File | New Projects Setup | Settings for New Projects.
On the Settings dialog that opens, go to Languages and Frameworks | PHP and click
in the Include Path tab to add paths to the required folders. 