Documenting components effectively by Doxygen

Question

How can you document components of your code such as the following effectively when the source codes of the components are in different locations?

Example of my components in my first database project

homepage - user_bar, check_login_status
    ask_question - form_ask_question
    login - form_login
    question_id - (form_login), form_answer, make_answer_list, make_question

I read the following command here

/** \addtogroup <label> */

However, I am not sure what is the right way of documenting components in source code.

Answer 1

1. components shouldn't be in completely different locations - they should be at least in the same package, namespace, directory, etc. Doxygen provides implicite grouping for all those.
2. apart from that, Module Grouping (the link you mention) is the way to go.