If it's the maximum from all records on the table, I would suggest using a 'helper' table.
You would relate all the contact records to the one single record on that table.
Related help table = 1 (Default this field to 1, so all contacts are automatically related to the only record on that table)
Then get the max version number through a summary up to the help table, then either
a) reference the help table directly in your pipeline
or
b) If the contact records are already part of your pipeline, lookup the max version number from the help table down to the contacts table.
