Hi @KJonsson,
HubSpot has two list types. One that accepts manual additions, one that runs on filters. The way each list type works contradicts each other. Filters would contradict manual additions/removals. That’s why it’s not possible directly.
If you want to be able to add companies manually, let’s assume you have active list A. Create another static list B. In your list A, create another filter “OR company is member of list B”. You can now add contacts to list B and they’ll automatically enter list A.
This is the closest you’ll get to manually adding companies to an active list without having to adjust the filter every time.
Best regards!