Method 1: Use new table occurrences to create new relationships to each of these tables. Double click the relationship line and specify that the records in the relationship be sorted by the modification date in descending order.
Say you have this relationship:
Voucher::VoucherID = RoomSales::VoucherID
create a new table occurrence of RoomSales by selecting it in the relationship graph and then clicking the button with two green plus signs so that you can set up this relationship:
Voucher::VoucherID = RoomSalesLatestUpdate::VoucherID
and set the relationship to be sorted as I described above. (Using a new relationship to a new table occurrence keeps the relationship options unchanged.)
Now you can refer to RoomSalesLatestupdate::UserName and RoomSalesLatestUpdate::Modificationdate to access the most recently modified data for that set of related records.
Method 2: create a layout (This layout will be hidden from the user) to Voucher and place portals on it to each of the related tables. Specify a sort order in each portal that sorts the related records by the modification date field in descending order. Use the Name box on the Inspector's Position tab to give each portal an object name. Scripts like this can then check the mod dates and other info in each portal:
Go To Layout [//layout with portals we just set up]
Go To Object ["RoomSalesPortal"]//use object name in quotes that you specified in the Inspector
Set Variable [$lastUpdate ; Value: RoomSales::ModificationDate ]
// and so forth
Go To Layout [original layout]
If "Table Occurrence" is a new concept, you might want to read this: Tutorial: What are Table Occurrences?
if you just wanna display the field, u could simply add the field in "modify table view", it should be displayed since u made the proper links between the related tables.
Or just add the field to list or form view layouts. All of those are different variations of "Now you can refer to RoomSalesLatestupdate::UserName and RoomSalesLatestUpdate::Modificationdate to access the most recently modified data for that set of related records."