- Create a Inbound search for getting Shipment number
Criteria : No need to add anything in here . You can add as per your requirement
Result : Shipment Number (Group) for removing Multi lines and Formula (Text)

Available Filters : Need To add “Item:PO” field for mapping each shipment with its Purchase order
Need to add a list/record field at first in available filters then only the search will
show in Sublist field
After creating the search create a sublist under a subtab and attach this search in to the sublist “SEARCH” field
Take a purchase order subtab created you can see the result and link attached for navigation