A custom Supplier Details in Item Doctype

Hi! everyone.
The screenshot you see above shows the default fields of the ERP V13 version under the ‘Item’ ‘Doctype.’ I customized a similar section for myself by adapting the ‘Supplier Details’ section that you can see here. (Note: Since the system didn’t allow me to make changes on default “Supplier Details”, so I created a similar one.)
My question is: I’ve created the equivalent of “Supplier Details”, but is there any underlying link within the system for the default “Supplier Details”'? How can I track this? Can you help me about this?