I have a couple BGP peers. I have inbound and outbound filters on each peer. In the filters I prepend each peer at one which currently makes them both equal at this point in time. I also accept all my subnets then drop all else. This all works fine.

I was just wandering if rather then filtering out going subnets on each peer I could filter my out going subnets on the BGP instance outgoing filter? This would simplify things I would think since when I add subnets I would only need to update my filters in one place.

If each peer does not require specific filter rules, then yes you can set those rules in instance out chain.

Another option would be to use a jump rule.

This could allow you to centrally manage the rules you want while still having a number of individual rules per peer. We use this for our bogon and transit vs peering announces.