Hydronic radiant heat in ceiling
You'd need custom heat spreaders, and it still won't work well

The heat spreaders used for hydronic systems only spread the heat along one face (so either a subfloor or the ceiling drywall). You would need to get a custom heat spreader for a single tube to do both.

A hydronic radiant ceiling also requires much higher temperatures than a floor does, so you'd have an uncomfortably hot floor or a rather ineffectively tepid ceiling. Neither is ideal.

You could run parallel systems between ceiling/floor joists

Two systems, with different temperatures, could be placed in parallel in the same space between joists. I can only speculate that it could work, but I've never heard of this before, so you might be venturing out a bit here.