Context:
I have merged MRP, repair and maintenance into 1 custom module called 'operations' simiarly to how openHRMS has done for HR. I am trying to get rid of the normal "manufacturing" settings menu and create my own custom one. I have successfully made my own menu. That was the easy part.

How odoo accomplishes this:
Odoo uses 2 methods. 1 method is to install a secondary module. Option 2 is what im trying to do. The MRP work order dashboard is not a secondary module but somehow odoo can hide and show the menu items based on the "work order" boolean.

Option 1 to accomplish task: 
Create secondary module(lets call it operations_dashboard). When the user clicks and make dashboard boolean true, we install seconday module. Secondary module adds menu item to custom operations module

Option 2: 
How do i do option 2? I can't figure it out. I have searched and searched in the source code but i can't find a lead to follow. I'd prefer to build the hide/show menu option into my module so i and other users don't have to install 5+ modules.