Category (Subjection) in R documentation for package

Hi,?
I am building package R-studio (Roxygen2).
In the package function documentation, now the standard format is to show all function name.

Now I want to categorize those function under some section/heading.
Can any one please hey me regarding this issue?
Is there any way or idea how one can do it ?



Regards.............Tanvir Ahamed 
Stockholm, Sweden???? |??mashranga at yahoo.com