The Admin Access Level Content tags extension allows you to set access level controls to sections of content based on the user groups defined in your Joomla 3.x settings.

Instructions:
{accesscontrol groupname}Text{/accesscontrol} This will allow the user of the specified group to see the text.
{accesscontrol groupname1, groupname2}Text{/accesscontrol} This will allow the user of the specified groups to see the text
{accesscontrol !groupname}Text{/accesscontrol} This will NOT allow the user of the specified group to see the text

Easy to use and very powerful for segmenting content to specific user groups on your site.

NOTE: You can use the WYSIWYG editor to format the content between the tacgs but you must not have the tags on the sam line for example:

{accesscontrol groupname}

Some Text or other formatted content here...

{/accesscontrol}

NOTE: This extension has been tested and works both in Joomla core articles and ZOO items. it may work in K2 and other CCK's but has not yet been tested for this.