Hi
Yes this is possible, I've just tried it on my server by using two users accounts and setting the properties differently for each;
Create two new recording profiles, one for you and one for dad (the settings for the profiles can be identical, separation happens at the user level below)
Create two users, one for you and one for dad
Assign your recording profile to your user account and your dads recording profile to his user account
On each user account, uncheck "View all DVR entries" and All DVR (rw) and save your settings.
This will mean each user has access to only his own recordings and no visibility of the other persons. The remaining configuration for the two users can be identical, even down to the recording path as the permissions will segregate them logically.
You could even allow/restrict specific channels per user by using 'exclude channel tags' or setting minimum/maximum channel numbers for each user.
You probably want to remove admin privileges from your dad too ;) Just uncheck the box in the user configuration screen.
If you need any more help just shout - I've also attached a screenshot of my mocked-up settings showing how to achieve what you're asking.
Jonathan.