I would think a list or table view of your data would work better as a way to effectively compare data from one adjacent record to another. This allows you align the fields of one record to another to make it easy to compare them.
But to do what you want is possible. Say you have a unique ID field in your table such as an auto-entered serial number or Get ( UUID ) value.
You could define a calculation field, cNextRecordID, as GetNthRecord ( UniqueIDField ; Get ( RecordNumber ) + 1 ) and set it up as an unstored calculation.
Then this relationship:
YourTable::cNextRecordID = YourTable 2::UniqueID
can work for your portal.