Implementing hidden content parts (as in old "Hidden Content" module)
You could use Block Class module to set blocks with some useful classes like &quot;only-role_name&quot;, etc. and hide/display it on your theme stylesheet.

Maybe even you could set a new block type and, if this type has its own css class (I'm not sure about it), use it to hide/display using, again, your theme stylesheet.

You could, too, use a new content type to create the block contents and Views to render this as blocks where you need. Views is able to restrict his view depending on roles or permissions.