The current way the Dat-O-Matic handles it requires you to not only select your region but also every permutation of it. My suggestion is just have you select your region and the Dat-O-Matic just includes every permutation that includes it. Here is an example, I used to one from the Game Boy Advance. Here it is currently but formatted to show everything better than the run on sentence it currently displays as.
Unknown---------------------Unset-----------------------------------------Argentina--------------------------------------------Asia
Asia, Australia--------------Asia, Korea----------------------------------Australia---------------------------------------------Austria
Belgium----------------------Brazil ----------------------------------------Brazil, Korea-----------------------------------------Brazil, Mexico
Brazil, Portugal--------------Brazil, Spain--------------------------------Bulgaria-----------------------------------------------Canada
China-------------------------Czechia--------------------------------------Denmark---------------------------------------------Europe
Europe, Asia-----------------Europe, Australia---------------------------Europe, Australia, New Zealand-------------------Europe, Brazil
Europe, Canada-------------Europe, Korea-------------------------------Finland-----------------------------------------------France
Germany---------------------Greece---------------------------------------Hong Kong-------------------------------------------Hungary
Italy--------------------------Japan-----------------------------------------Japan, Asia------------------------------------------Japan, Asia, Korea
Japan, Australia------------Japan, Australia, New Zealand------------Japan, Brazil-----------------------------------------Japan, Europe
Japan, Europe, Australia--Japan, Europe, Australia, New Zealand--Japan, Europe, Australia, New Zealand, Taiwan-Japan, Europe, Brazil
Japan, Europe, Korea------Japan, France-------------------------------Japan, Hong Kong-----------------------------------Japan, Korea
Japan, New Zealand--------Japan, Taiwan------------------------------Japan, USA--------------------------------------------Japan, USA, Brazil
Japan, USA, Korea----------Korea----------------------------------------Latin America----------------------------------------Mexico
Netherlands------------------New Zealand--------------------------------Norway------------------------------------------------Poland
Portugal----------------------Romania-------------------------------------Russia-------------------------------------------------Scandinavia
Spain-------------------------Sweden--------------------------------------Taiwan-------------------------------------------------UAE
United Kingdom-------------United Kingdom, Australia-----------------United Kingdom, Sweden---------------------------USA
USA, Asia--------------------USA, Asia, Korea----------------------------USA, Australia---------------------------------------USA, Brazil
USA, Europe-----------------USA, Europe, Australia---------------------USA, Europe, Brazil----------------------------------USA, Europe, Korea
USA, Hong Kong-------------USA, Korea----------------------------------USA, Taiwan-------------------------------------------World
Now, here is it with the repeats taken out.
Unknown---------Unset----------------Argentina-------Asia
Australia---------Austria--------------Belgium----------Brazil
Bulgaria----------Canada-------------China-------------Czechia
Denmark---------Europe--------------Finland-----------France
Germany---------Greece--------------Hong Kong-------Hungary
Italy--------------Japan----------------Korea-------------Latin America
Mexico-----------Netherlands---------New Zealand-----Norway
Poland------------Portugal-------------Romania----------Russia
Scandinavia-----Spain-----------------Sweden----------Taiwan
UAE--------------United Kingdom-----USA---------------World
Infinitely more readable and with less chances to mess up when choosing your regions. In the first one, you have to hit 15 different boxes just to select the USA region games as opposed to just hitting USA in the other one. And how often do you really have users wanting to select the games that came out exclusively to the USA but nowhere else or games that came out in the USA and Europe but not the ones that came out in the USA, Europe, and Korea?
Edit: Sorry, the website removed all the formatting.... Went and redid it as best I could.