Can a module have 2 parent modules?

IN ERP, Material Request is present in ‘STOCK’ as well as ‘BUYING’.
Is it possible one module can have 2 parent module??

Yes it is possible. It points to the same thing but it is just made available from two places for easy access.

Ohh great… how can that be done??
I want to make opportunity visible in CRM & Selling module

You will have add it to selling.py file same as for Address or any other link:
https://github.com/frappe/erpnext/blob/develop/erpnext/config/selling.py#L44-L46

OK thanks… Its done