This is how you add a new option under a module in the Main Menu on top of the screen.
Lets say you want to add an option “Process Leads” under the Leads module. To do this:
1. Create a new file in custom/Extension/modules/Leads/Ext/Menus. If the Menus folder doesn’t exist, just make one. We can name the file menu.php.
2. On menu.php file, input codes below:
<?php global $module_menu; // This will add the new option $module_menu=Array("index.php?module=Leads&action=ProcessLeads", "Process Leads", ""); ?>
In the example above, we assume that the action ProcessLeads is an existing file under custom/modules/Leads with the name ProcessLeads.php but you can also map actions with files.
3. Just run Repair and Rebuild then logout to see the changes.