I think I saw a compass course indicator, too. And that brings up a whole other thing from BSG: An artificial horizon instrument in space?
Readouts that are anachronistic, inappropriate, or whatever the word is aside, pretty much all useful standard 3D coordinate systems have a stage at which the spatial coordinates are defined relative to a plane: Cartesian (z perpendicular to xy plane, vice versa, or any other combination of one axis vs two), spherical (zenith perpendicular to polar plane or vice versa), cylindrical (polar plane perpendicular to cylindrical axis or vice versa), etc.
In any case, three noncollinear points define a plane. Further, it's worth noting that gravitational two-body orbits are planar (in an inertial coordinate system).
Some ideas:
Coordinates for a battle plan might be specified in terms of
Galactica's intended (and unperturbed) orbital plane as it guards the fleet that's jumping into hyperspace, and the Vipers' horizon plane is set equal to that. Or maybe three noncollinear points of interest define the Vipers' initial horizon plane, centroid of enemy Base Stars at launch (1),
Galactica at launch (2), and expected position of
Galactica when all civilian ships have jumped (3), with action therefore expected near or in that horizon plane, but with the option to reprogram, as during landing (as mentioned) or perhaps as the
Galactica or Base Stars enter new orbits. Maybe the pilot can switch among a variety of preprogrammed coordinate systems.
