The person born there in 1900 had connections with a part of the Czech Republic which gained it's independance from Austria-Hungary in 1918-20, and was returned to Hungary 1938-45. Presumably that area is back in the Czech Republic now.
No parts of the Czech republic were given to Hungary during that time, all the land was part of Slovakia. As for where it is now, almost of the land taken by Hungary in 1938 is now in Slovakia and most of the land taken in 1939 is now in Ukraine.