Based on the provided tables (showing Sales team channels and Planning/Budget channels with their privacy, roles, and members), User1 can see the membership list of the Budgets channel.

Non-members of a private channel cannot view its member list; private channel membership is restricted to existing members and channel owners, so User1 having access is incorrect.

The Budgets channel is configured as a private channel, meaning only its members can see the membership list. Based on the provided tables, User1 is not a member of the Budgets private channel, so the membership list is hidden from User1 entirely, regardless of their role in the parent team.