Unable to prepare the filter in Supplier Child table when new Item is added in Item child table of RFQ doctype

In the Supplier doctype I implemented an Item group child table. For the Supplier child table of RFQ I am preparing a filter as Filter the supplier based on Item groups(available in supplier doctype) matching with the attached items available in the Item child table. This filter works fine for the current row. When a new item is added in RFQ, the updated supplier list is not filtered for the current row in the supplier child table. Now if a new row is added in the supplier child table, the updated filter list is reflected. Can anyone provide thoughts regarding the same? Any help is appreciated.