I don't know if you can assign it to more than one group. But for users you can assign everyone you want to have access to a user group (I talk to my local Qualtrics administrator to do this). Then when you are under Contacts or the Library make sure you are in the correct group view that you want to have access to the list. My profile seems to default to just my view. So I have to go to the top left hand corer where I see my name, choose the drop down, and change it from my single-user account to the group name.

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