Good News!
With the latest update for Nintex Forms (2.8.1.0) List Lookup Control has been enhanced.
In the release notes you find: "Fixed an issue where the List Lookup filter may not work when Source View specified."
So with that fixed, you now have the possibility, to filter data with multiple parameters, based on your Source View.
For example:
I have a SharePoint-List named "Contracts" and I only want to display items of a particular company, where Currency Status equals "Active".
Configuration of my List Lookup Control looks like this:
And the result is very #2015
(Note: Currently, "CompanyName"-Control has to be a Single Line Text Control. Calculated Value Controls are not supported (yet?))