Show a field on the on a tab only to certain user groups (ACL)

Hi,
ho can i set up a field that is displayed only to a certain user acess level?
i have some sensitiv data that should be visible if a moderator of my site will look on the profile but the user himself should only see this field on his registration form.
other users should not see the field in any case.
thanks in advance for your help!
cheers
carsten

Currently the best way to do this is move the tab the fields are on to a not shown on profile position. Then create a new tab that is only accessible to your moderators. Next using Delimiter fields you'll substitute in the fields on your tab that is in a not shown on profile position (e.g. [cb_myfield]). More on substitution usage can be found in the tutorial below.

www.allmysocials.com/directory/tutorials/item/233-substitution-usage