Hi Hae-Jong,
I am not too sure what you are asking. Therefore some more detail on what you are trying to do and what you have already tried may be helpful in better answering this question. Here is some info on adding multiple files to a coder project.
For a coder project the workflow is to specify an entry-point function and all dependent files are automatically included. You can add an entry-point file by selecting "add files" in the Coder UI. This is located in the "Overview" tab in the "Entry-Point Files" section. Note that any dependent files not in the current working directory need to be on the MATLAB path.
If you would like to generate code for multiple entry-points (in your case multiple files in the current directory) just add them as individual entry-point files. After pressing "add files" you can select multiple files using the file browser.
