Fetch from second/third level relations

How to fetch data over multiple relations?

For example I create a new DocType with a link field to patient (Healthcare).
From patient I would like to get the customer and from customer I would like to get the primary_address and from that the Address Line 1.
I assume it is not possible to fetch something like patient.customer.primary_address.address_line1 is it?

Is there a way to do it via customize form or do I have to start coding? If yes, any coding example that would get show how?

check this.