You shouldn't use globals anyway. But yes: as long as you don't declare a variable as global, you can use it as a normal variable with that name in another function.
function foo1
global x
x=x+1;
disp(x)
end
function y=foo2
x=1:4;%not a global, just a normal variable
y=x.^2;
end
If you really must use a global, give it a very long name, which includes the function name and a description. Copy the contents to a variable with a shorter name for readability, and then copy the results back to the global.
function foo3
global x_coordinates_in_foo3__used_for_the_x_coordinate_of_something_important
x=x_coordinates_in_foo3__used_for_the_x_coordinate_of_something_important;
x=x+5;
x_coordinates_in_foo3__used_for_the_x_coordinate_of_something_important=x;
end
