If you use Navigation blocks (not the traditional sidebar/widget approach) then you could also use this approach:
- Enclose one Navigation block within a Groups Non-member block for the Registered group. Use Menu A with this Navigation block.
- Enclose a second Navigation block within a Groups Member block for the Registered group. Use Menu B with this Navigation block.
- Use separate menus for these two with the items as required, here we have two Menus, A and B. For your case, the page for non-registered visitors goes in Menu A, the second page for registered users goes in Menu B.
Also noteworthy, in the upcoming Groups 2.20.0 we add support for having items hidden automatically in Navigation blocks for Page Link items that point to existing pages – this is already implemented in the https://github.com/itthinx/groups/tree/tested-2.20.0-6.4 branch if you want to try that. Note that this works for Page Link menu items, not for plain Links where you input the URL manually.