Q:

Permissioning on list based on group

I have list for of items added by users who belongs to one of the 3 departments. I want that user can only see the item added by them. Each department will have an approver who can see all the items added by the user of his department. 
Edit: Thanks to the fellow members I was able to filter the users to see only item created by me. The complicated part is I have 3 user groups and each group has one approve which I have maintained in another list

Now I have added an approver column in the main list which I want to be automatically populated based on the user accessing the list( will need to determine the group which user belongs and then determine the approver of that group from the Group Approvers List). 
Can anybody help me how I can achieve this or any other approach.
For Approver Filetering, I will add the filter based on the approver column.

A:

If you're in a Custom List, you can go into Advanced Settings and change the Item Level Permissions settings. The options here configure whether your users can see all items, or see just items created by them. You can also set the creation rules here; whether a user can create and edit all items, create items and only be able to edit their own, or not have any create/edit rights. 
You could then put your 'approvers' in their own security group with the 'Cancel Checkout' permission so that they can see all items, or even just place them in the approvers group (as long as that group doesn't have permissions elsewhere).
The issue with creating views as David mentioned is that any view is accessible through the URL. Unfortunately, you cannot place permissions on views out of the box.
Hope that helps! 

