Hiding/Showing items depending upon list meta-data

Scenario:
You want to toggle visibility of the list items depending upon particular audience.
i.e Group A should be able to see some documents/items if one of the meta-data field says A.

Solution:
List Audience Targeting

Steps:
1. Create various different Audience in Share Service Provider with rules using MetaData.
2. Go to the List > 'Advanced Settings'
3. Click on 'Audience Targeting'
4. Select 'Enable Audience Targeting'
5. You will get an extra column for each item 'Targeted Audience'
6. Specify the created audience and this will toggle the document/item visibility.

Note:
Audience is not Security as user can still reach to the item if he know the Url.

Article:
Code Guru