How to fetch data from child to another child tabel to custoumize material request item

Hi all comunity
i added custom form A as child table with Tow fieldtype all of Link datatype from User DocType
and i added the same Tow custom fieldtype to the Item DocType and also i did to material request item
so :
Custom form A with 2 link-able field type.
same 2 field added to Item DocType.
same 2 field added to material request Item DocType.
which i need is when i make new material request item when i select the item all other item field should be automatically fetched which already done but i want my Tow customized field also fetched automatically as the other Item Fields in the material request item?

thank you all

From custom script you can fetch the same fields in any document.