How do I hide wiki access on the dashboard backend?

I am using the wiki (not Lite) in a company intranet site with membership levels. All levels, have the capability to make posts, and all levels except the lowest have wiki viewing capabilities.

How can I restrict access to the wikis on the backend from all membership levels except the top 4 (I have 6 levels)? I can't select wiki editing privileges for 'users who can edit posts in this site' because that includes the lowest level.

In the membership plugin (WP eMember) content protection I have granted access to the wikis for the top 5 membership levels and that is so they can be viewed on the frontend.

In the Simple Intranet plugin I have set capabilities so that posts and wikis can only be read by the proper levels, but when testing they still have access on the backend.

I know this sounds confusing, sorry about that, but there are so many places to make changes and adjust settings, but this one I can't seem to figure out.

Thanks for your help.