@OFFSET in SPSS Clementine Explained:

 
A few years back I asked Satheesh from Elite Analytics what the @OFFSET function in SPSS Clementine was for. He provided the following explanation (paraphrased):
 
@OFFSET basically allows you to access the value of any record other than the current one. 
 
Code:
 
@OFFSET(X, 1) – points to the value of the previous record
@OFFSET(X, 2) – points to the value of the record prior to the previous record
@OFFSET(X, -1) – points to the value of the next record
 
Example: (click images to enlarge)
 
Original Data Set
 
Offset used in derive node
 
@OFFSET Results
 
In the resulting data set after @OFFSET is applied, note how the value on the Monday row for the OFFSET_FUNC is null. That is because in the table, there is no other value before the values for Monday.
 
You can also download the stream and data file testing on your local environment.