Field::getConfigInputfields() method   
Get any Inputfields needed to configure the field in the admin.
Usage
$inputfieldWrapper = $field->getConfigInputfields();Return value
Hooking $field→getConfigInputfields()
You can add your own hook events that are executed either before or after the $field->getConfigInputfields() method is executed. Examples of both are included below. A good place for hook code such as this is in your /site/ready.php file.
Hooking before
The 'before' hooks are called immediately before each $field->getConfigInputfields() method call is executed. This type of hook is especially useful for modifying arguments before they are sent to the method.
$this->addHookBefore('Field::getConfigInputfields', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $Field = $event->object;
  /* Your code here, perhaps modifying arguments */
  // Populate back arguments (if you have modified them)
});   Hooking after
The 'after' hooks are called immediately after each $field->getConfigInputfields() method call is executed. This type of hook is especially useful for modifying the value that was returned by the method call.
$this->addHookAfter('Field::getConfigInputfields', function(HookEvent $event) {
  // Get the object the event occurred on, if needed
  $Field = $event->object;
  // An 'after' hook can retrieve and/or modify the return value
  $return = $event->return;
  /* Your code here, perhaps modifying the return value */
  // Populate back return value, if you have modified it
  $event->return = $return;
});   API reference based on ProcessWire core version 3.0.252