You can add parameters to menu types. This is done in the default.xml file in tmpl folder.

site/views/helloworld/tmpl/default.xml

<?xml version="1.0" encoding="utf-8"?>
<metadata>

<layout title="Hello World Message">
<message>Displays a message</message>
</layout>

<fields name="request">
<fieldset name="request">
<field
name="id"
type="list"
label="Greeting Type"
description="Select type of greeting to display"
default="1">
<option value="1">Hello World!</option>
<option value="2">Good bye World!</option>
</field>
</fieldset>
</fields>

</metadata>

The request group of fields indicates mandatory fields. 

The name attribute can be passed to the component in the URL. In this example, ?option=com_helloworld&id=1 would indicate that you had chosen option 1.

Now, the model has to be modified in order to switch between the two different messages depending upon which is chosen by the administrator.

site/models/helloworld.php

class HelloWorldModelHelloWorld extends JModelItem
{
protected $message;

public function getMsg()
{
if (!isset($this->message))
{
$jinput = JFactory::getApplication()->input;
$id = $jinput->get('id', 1, 'INT');

switch ($id)
{
case 2:
$this->message = 'Good bye World!';
break;
default:
case 1:
$this->message = 'Hello World!';
break;
}
}
return $this->message;
}
}