Create Sub domain on Wordpress and link database

Create a sub domain on my Wordpress , saparating my community site and e-commerce .

I’m using buddypress for my community site and wanted to linked both database for woocommerce and community.

I will have mycred points to be earn in community sub domain and can be spend on my e-commerce on main domain .

I need someone who can work on direct admin for my hosting to set thing up