Steps to create a custom metadata schema form field - Accordion component.

I want to added a custom field that can show/hide a set of fields similar to Accordion or create a composite multi field. Generic use case can be to add : Multiple  Address[with Multi[Address lines],state,city and county] as metadata.

Please suggest if we have any documentation or clear step to create a custom multi-multi feild into this Form. I understand I have to do below steps but

1. Update  /libs/dam/gui/coral/components/admin/schemaforms/formbuilder/builditems.jsp

2. Create a custom component /libs/dam/gui/coral/components/admin/schemaforms/formbuilder/formfields

Looking for what are must items that needs to be performed in creating my custom component will be very useful.