Source

File: wp-includes/link-template.php

function user_admin_url( $path = '', $scheme = 'admin' ) {
	$url = network_site_url( 'wp-admin/user/', $scheme );

	if ( $path && is_string( $path ) ) {
		$url .= ltrim( $path, '/' );
	}

	/**
	 * Filters the user admin URL for the current user.
	 *
	 * @since 3.1.0
	 *
	 * @param string $url  The complete URL including scheme and path.
	 * @param string $path Path relative to the URL. Blank string if
	 *                     no path is specified.
	 */
	return apply_filters( 'user_admin_url', $url, $path );
}