Jeff,
On ours, the ref filter is mounted pointing pass side to drivers side.
Ours: From the pump output, blue pex water pipe goes down and hooks around to a tee fitting for the ref water filter, and then out to the rest of the coach and low point drain. From the tee fitting, the blue pex is reduced to 1/4 flex tube, then short run to a 90deg turn shutoff for the filter, then to the push on compression fitting on the filter input itself, through the filter and out to the ref.
If you need a quick picture, feel free to ask..
I've seen one coach that replaced some of their lines and short runs by the water pump with different pipe sizes and fittings based on the upgraded type of ice maker water filter that they had purchased, so I wasn't sure if your is still orig or not...