I'm not sure if I understand the question, because the answer seems to be trivial:
function calling
file1
file2
That's it. Perhaps you want some inputs or output?
function Output1 = calling(Input1)
disp(Input1);
file1(375);
file2('This is a string');
Output1 = 'ready';
Does this help already? If so, I recommend to read the "Getting Started" chapters of the documentation, where such basics are explained.