Restricting Leave Approvers to view specific Department's Leave Applications

How to restrict Leave Approvers to get notifications and view only those Leave Applications that have been applied by employees of specific Department? The Leave Approver has been set as ‘Leave Approver’ in the ‘Department’ doctype.

Currently all the Leave Approvers are able to see all the applied Leave Applications.

Have a look at User Permissions and you should be able to figure it out

If setting of User Permissions needs to be done in Leave Application for specific Department, then what is the actual need and effect of setting Leave Approvers in the Department doctype ?

Leave Approver can only see leave applications by specific department?

Yes, only the assigned Leave approver of the Department to be notified about Leave Applications applied by Employees of that specific Department.

This may can help you.

it restricts the approval action to only those who are assigned that role.

Now say you want Boss A to approve leaves for dept X, then permit him only Dept X in User Permissions.