Hi Mirella,
You can't reference a common field amongs smart list members in a smart list.
Here is what you can do. you'll have to pull a new smart list that looks for:
Filter 1: Company name is: use same list of companies used (you may have to export your other smart list and sort by company then pull those companies in to your new smart list filter)
Filter 2: Member of smart list not in [your first smart list name]
Unfortunately you'll have to pull the companies in each time you want to run the report.
Thanks,
Tara