Or maybe
this one
. Just found it at JED
How Ninja Access works
Hide content using this plugin by surrounding the content you want to be seen by certain groups in a tag. Ninja Access uses numbers to specify which group the content includes:
{njaccess 0} Shows this content only to guests {/njaccess}
{njaccess 18,19,20,21,23,24,25} Shows this content to all users who are guests {/njaccess}
{njaccess 24,25,30,31} Shows this content to administrators and 2 custom groups created in JACL {/njaccess}
When content is not shown to a particular group, the text is simply hidden.
As you can see from the examples above, you need to know the default Joomla GroupIDs: 0 - Guest, 18 - Registered, 19 - Author, 20 - Editor, 21 - Publisher, 23 - Manager, 24 - Administrator, 25 - Super Administrator.