Add a button like 'New Address' for New Doctype Linked to Supplier DocType

I currently trying to implement a fix for this issue: https://github.com/frappe/erpnext/issues/5224

Long story short, for each Supplier several Supplier Certificates can be related. I wan to create the same functionality with Address and the button ‘New Address’. From that I see, Address DocType is linked to Supplier DocType with ‘Address HTML’ Doctype.

Is there some documentation on how I can implement this fix? Has anyone tried any similar and give some pointers?

Address, Contact list is custom coded via JS