Change Membership Level Checked Out According to Register Helper Input

change-membership-level-on-rh-selection.php

<?php
/**
 * This will change the user's membership level if the user selects 'lessthan2000' on th custom field.
 * Adjust this code to match your needs. Please note that if the initial level checking out is free, 
 * and you want to assign to a paid level depending on field selected, you may need to adjust the new level's price to $0 or ensure both levels are free or paid.
 * 
 * Add this code to your PMPro Customizations Plugin - https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
 
 function my_pmprorh_init()
{
	//don't break if Register Helper is not loaded
	if(!function_exists( 'pmprorh_add_registration_field' )) {
		return false;
	}
	
	//define the fields
	$fields = array();
	$fields[] = new PMProRH_Field(
		'budget',						// input name, will also be used as meta key
		'select',						// type of field
		array(
			'options' => array(				// <option> elements for select field
				''		=> '',			// blank option - cannot be selected if this field is required
				'lessthan2000'	=> '&lt; $2,000',	// <option value="lessthan2000">&lt; $2,000</option>
				'2000to5000'	=> '$2,000-$5,000',	// <option value="2000to5000">$2,000-$5,000</option>
				'5000to10000'	=> '$5,000-$10,000',	// <option value="5000to10000">$5,000-$10,000</option>
				'morethan10000'	=> '&gt; $10,000',	// <option value="morethan10000">&gt; $10,000</option>
			)
		)
	);
	
	//add the fields into a new checkout_boxes are of the checkout page
	foreach($fields as $field)
		pmprorh_add_registration_field(
			'checkout_boxes',				// location on checkout page
			$field						// PMProRH_Field object
		);
	//that's it. see the PMPro Register Helper readme for more information and examples.
}
add_action( 'init', 'my_pmprorh_init' );

function my_pmpro_checkout_level($level)
{
	
  if ( ! empty( $_REQUEST['budget'] ) && $level->id == '4' ) {

	  if ( $_REQUEST['budget'] == 'lessthan2000' ) {
	  	$level->id = '6';
	  }

  }
 
  return $level;
}
add_filter("pmpro_checkout_level", "my_pmpro_checkout_level");