section with in a section config file and reading that config file

[kampy]

hi all,
my requirement is to have section with in a section in config parameters
ex:
[AAA]
    [BBB]
     a=1
     b=1
    [CCC]
     a=1
     b=2
Any one help me in  understanding how to make sure that config file to have a structure like this and reading with the config parser