You can do the same thing in Oracle Load Testing. In your scenario, add your script twice.
For the first occurrence of your script configure the databank of users to only use the USER1 row, and configure that script to use rows 1-10 in the 2nd databank file.
For the second occurrence of your script configure the databank of users to only use the USER2 row, and configure that script to use rows 11-20 in the 2nd databank file.
The key is to have a separate occurrence of the script your scenario.
Yes it would be tedious for a large number of users. OLT does a nice job of managing databank records - if there is no specific reason forcing USERS to process SPECIFIC rows, just let OLT manage it for you. If each row in DATABANK 2 can only be processed once - just configure that databank to stop once it is out of records.
You may have some USERS who iterate 21 times and others who iterate only 19 times - but that shouldn't matter. It is still putting the same load on your back-end infrastructure - and that is what is important.