Fetch child table data of one doctype to another child table of another doctype

Hi all… i have two doctypes site details and site planning. each having child tables namely Tiffin details and Site Planning Item.
i want to fetch no of tiffin from tiffin details into site planning item table.

For example: if i add a row in tiffin details as for type Dal the no of tiffins are 5[Image 1] i want that no of tiffin value in a dal field of site planning item .
How to proceed. Please help!!

it is fetching site name and labour count from site details as they are present over form.

please refer this query