field.php

<?php
	array(
	'id'=>'text',
	'type' => 'text',
	'title' => __('Test Compiler', 'redux-framework-demo'),
	'subtitle' => __('This is to test the compiler hook.', 'redux-framework-demo'),
	'desc' => __('Each time this field is set, a flag is set. On save, that flag initates a compiler hook!', 'redux-framework-demo'),
	'compiler' => true,
	'default' => 'Test Compiler'
	),	

hook.php

<?php
/**
   This is a test function that will let you see when the compiler hook occurs. 
   It only runs if a field	set with compiler=>true is changed.
**/
function testCompiler() {
	echo "Compiler hook!";
}
add_action('redux-compiler-redux_demo-sample-file', 'testCompiler');
// This hook assumes your opt_name is redux_demo. Replace with your own.

This should be updated as "-sample-file" isn't needed.