[Skulemate]

You first characterize each leg of the flow as a length of pipe or tubing that has the same resistance curve as the fittings, blocks or whatever else you are dealing with. Once this is done you can represent both legs together as an equivalent length of tubing in order to solve for the flow rate (and Dp) for your given pump. After this is done you can back-calculate to find the flow through each leg of the setup, and for the resistances of each component.

If this brief explanation doesn't help you understand, I can work out a brief sample tonight if you like.