Select File from UI Menu With Specific File Type

Basically my game reads a file, goes through a parser that I personally programmed and using the out put of that parser it spawns blocks with words in the game. I have the parser and the object spawner working perfectly. But I would like to be able to select a different file from a UI menu. And I only want to accept a specific file type. (Like a .py file) I want to have a blueprint callable function that can read and display files of the file type. From that I think I can figure out how to make that interactive and feed the file name to my parser.