Simply put, have separate callback functions for each trigger. It's kind of a crappy solution, but the only one that's really possible. It would have been nice if the trigger was passed to the callback function, but it isn't.
What you can do, if there is a significant amount of code in the callback, is just have small dummy callback functions that call the real code, and pass a parameter to distinguish where it's calling from.
export void Callback1()
{
DoWork(1);
}
export void Callback2()
{
DoWork(2);
}
...
void DoWork(int i)
{
...
}