Class not found when loading a library

Hi, I have some libraries created under a subdirectory inside Library folder:

../app/Libraries/commonLibraries/

Inside this folder, i have 10 different libraries that i will use in a lot of parts of the web application.

The problem is that inside a library y may have different classes, and i would like to initialize this classes (the classes names are different of the file name)

Example:

I have a library that is: /app/Libraries/commonLibraries/FileDoSomething.php

Inside this library, i have a class defined that is :

class anythingToDo{
...
}

How can i create an object anythingToDo in another part of the project that is not in the FileDoSomething?