django - how to group user inputs for community based mapping app? -

me , friend of mine working on app gets input (map issues or information user think it's worth sharing) users specific location.

our primary data stored in mongodb. has lat, long, address , zip code each datapoint have particular city.

my question is:

how group multiple user inputs same datapoint? example user can add information place. , user can add similar info same place 2 blocks away. how group both inputs?

any data-model or algorithm suggestions welcome.

ps: framework using django