Add CSS to only show member Member Links on the PMPro Account page for affiliates.

pmpro-show-member-links-for-affiliates-only.php

<?php
/**
 * Show member links on the account page only to affiliates.
 *
 * 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/
 */
function pmpro_show_member_links_for_affiliates_only() {
	// bail if pmpro_affiliates_getAffiliatesForUser() is not available
	if ( ! function_exists( 'pmpro_affiliates_getAffiliatesForUser' ) ) {
		return;
	}

	$affiliates = pmpro_affiliates_getAffiliatesForUser( get_current_user_id() );

	if ( empty( $affiliates ) ) {
		?>
		<style>
			#pmpro_account-links {
				display: none;
			}
		</style>
		<?php
	}
}
add_action( 'wp_head', 'pmpro_show_member_links_for_affiliates_only' );