Remove columns from the PMPro Memberslist CSV export.

pmpro-remove-members-list-csv-headings.php

<?php
/**
 * This recipe removes defined column headers from the Members Export CSV
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

 // Remove column headings
function my_pmpro_members_list_csv_heading( $csv_header ) {

	$heading = explode( ',', $csv_header );

	/*
	 * Add or remove the column headers that you
	 * would like removed in the $remove array.
	 */
	$remove = array( 'discount_code_id', 'discount_code' ); // remove discount code and discount code id

	foreach ( $heading as $key => $title ) {
		if ( in_array( $title, $remove ) ) {
			unset( $heading[ $key ] );
		}
	}

	$csv_header = implode( ',', $heading );

	return $csv_header;
}

add_filter( 'pmpro_members_list_csv_heading', 'my_pmpro_members_list_csv_heading' );

// Remove column data
function my_pmpro_members_list_csv_default_columns( $default_columns ) {
	$new_default_columns = array();
	$remove              = array( 'id', 'code' ); // remove discount code and discount code id

	foreach ( $default_columns as $key => $value ) {
		if ( ! in_array( $value[1], $remove ) ) {
			$new_default_columns[] = $value;
		}
	}

	return $new_default_columns;
}

add_filter( 'pmpro_members_list_csv_default_columns', 'my_pmpro_members_list_csv_default_columns' );

The default column name can be obtained from here
https://github.com/strangerstudios/paid-memberships-pro/blob/2b372ffdd0131ec5e1427033f4cc3730993bf304/adminpages/memberslist-csv.php#L97-L119