DSXchange

I guess it would depend on the value or values you do want.

FIELD1='SOMETHING'
this is simpler then then other

but again it depends on the values you want.

In this case field1 can be many values, but it's easier for me to check for the values I don't want rather than checking for the values I do want. Is there a way to do a NOt IN() statement within a filter stage?

The Filter stage "supports standard SQL expressions" so why not give that a try?

Note, in particular, the non-appearance of IN in that list.