Restrict BuddyDrive to a specific capability. More info about bp-custom.php > https://codex.buddypress.org/themes/bp-custom-php/

bp-custom.php

<?php
/**
 * Get the required cap.
 *
 * For info about Capabilities
 * @see https://codex.wordpress.org/Roles_and_Capabilities#Capability_vs._Role_Table
 */
function wpsouf_get_required_capability() {
	return 'manage_options';
}

/**
 * Restrict user nav to a specific cap.
 */
function wpsouf_restrict_nav_to_capability() {
	$bd      = buddydrive();
	$user_id = bp_displayed_user_id();

	if ( ! $user_id ) {
		return;
	}

	// Check user's cap and eventually remove BuddyDrive Nav
	if ( ! user_can( $user_id, wpsouf_get_required_capability() ) ) {
		bp_core_remove_nav_item( 'buddydrive' );

		// If current user
		if ( (int) $user_id === (int) bp_loggedin_user_id() ) {
			$bd->user_hasno_access = true;
		}
	}
}
add_action( 'bp_buddydrive_setup_nav', 'wpsouf_restrict_nav_to_capability' );

/**
 * Restrict WP Admin Bar or BuddyDrive user link to a specific cap.
 */
function wpsouf_restrict_admin_bar_and_link_to_capability( $retval = '' ) {
	$bd      = buddydrive();
	$user_id = bp_loggedin_user_id();

	if ( ! $user_id ) {
		return $retval;
	}

	if ( isset( $bd->user_hasno_access ) ) {
		return false;
	}

	if ( ! user_can( $user_id, wpsouf_get_required_capability() ) ) {
		return false;
	}

	return $retval;
}
add_filter( 'bp_buddydrive_admin_nav',        'wpsouf_restrict_admin_bar_and_link_to_capability' );
add_filter( 'buddydrive_user_buddydrive_url', 'wpsouf_restrict_admin_bar_and_link_to_capability' );