custom sorting BuddyPress member types in the member type field by their creation order in member types pro

member-types-field-options-sort.php

// custom sorting of member types on registration page
// by the creation order in member types pro plugin.
add_filter( 'bp_xprofile_member_type_field_allowed_types', function ( $member_types, $registered_types ) {

	if ( empty( $member_types ) || ! function_exists( 'bpmtp_get_active_member_type_entries' ) ) {
		return $member_types;
	}
	// find all our active types(Member Types Pro plugin)
	$active_type_objects = bpmtp_get_active_member_type_entries();
	// sort by post_id(it is similar to creation order)
	$active_type_objects = wp_list_sort( $active_type_objects, 'post_id', 'ASC', true );
	$active_keys         = array_keys( $active_type_objects );

	return array_replace( array_flip( $active_keys ), $member_types );

}, 10, 2 );