I've got the Hayward EC65 DE Filter...the kind with the fingers and the kind you bump. No backwashing.
Currently, the output of my pump goes to my filter. The output of my filter goes to the sole input of my valve. My valve has 2 outputs...one for each return. I can set it so that either one is on, both are on, or both are off.
What I need now though is the same set up, except that I need my valve to have 2 inputs...One from the filter, and one from the pump. This way I can bypass the filter when I need to (I've had a need to a few times and wasn't able to).
Do they make valves with this configuration? If not, I'll need an extra valve like I currently have, as drawn out in option c below.