I'm not sure how that line is routed. Hopefully you can find a schematic. Probably runs under the headliner.
The service manual may have a diagram of the hose routing. There's a link to download the service manual elsewhere in the forum. FWIW, I believe the hose runs from the reservoir, up the A pillar, along the gutter seam between the roof and body, across the rear of the roof to the liftgate, and terminates at the rear washer nozzle.
When I try to use the rear washer fluid it sounds like fluid is in the drivers a pillar. ... Anyone have an idea of an easy ish fix?
If you can find a break in the hose inside the A pillar, you may be able to fix it with a hose splice. You'll have to know the hose ID (inside diameter) in order to pick the correct splice.