WordPress Plugin - AJAX Combobox for State, City and Neighborhood

I need a plugin that when installed, provide a Metabox into new posts page in WordPress Admin. This metabox will must have a dynamic combobox (AJAX), where the user can select the state, the city and finally the neighborhood. That is, first you select a state, then the second list button will be updated via ajax to present the cities related to the selected state, and the final list will be updated with the neighborhoods available for the city previously listed. Not is necessary to persist the selected information in the database, I just need of the metabox that makes reading dynamically. However, the consultation will be held in custom tables within the database. Are three tables, one for the states, one for cities and one for the neighborhoods, they are properly outlined with IDs to the interweaving of information between a table and another. These tables with content will be made available to carry out the work. It is imperative that the development takes place for the sole use of WordPress API, ie, without the use of additional third party plugin.