To create a standalone MATLAB application that includes a fixed data folder and allows the user to select another data folder, you can design the application in MATLAB App Designer and compile it into a standalone application using Application Compiler.
Add the path to the fixed folder in the App using App designer and use the “Files required for your application to run” section to add the files and folders required to package and run.
You can learn more about creating Standalone Application using Application Compiler App here.