How to get AD group Names in my app

hi everyone i am new. i am making one app to provide easy data transfer and communication in hospital.

so i am integrating hospital AD with openfire. In AD there is grouping. i am getting all the groups with listed users correctly. my problem is i want to list the users with there belongings groups(AD groups), but i dont know how to get that groups. i am getting the local group names what an user enters at th time adding roster, but could not get the original AD groups.

plz help .

Thanks