Do passive RC filters need ground?

So, after a bit of searching I can’t seem to find an answer to this anywhere, at least not in an easy to understand manner.

Ok, lets set a scenario, if we have an audio input (in my project it would be buffered by a op amp in a 3403 quad op amp IC) and have that go into a passive RC filter (possibly 3 band) and have the output of that go into an overdrive circuit.

Question: Does that RC filter need a ground to filter to, or could I instead wire that to a second “identical” overdrive circuit and have part of my signal filter to od1 and the other part to od2?

Just a curious question, since all I can find are explanations of how RC filters filter to ground, but as I understand it, the filter works by having the “unwanted” frequencies follow a path of least resistance to ground, by that logic I would think that it doesn’t matter whether that path is to ground or to some other part of the circuit.

Edit 1: Hypothetical schematic added.

^{simulate this circuit – Schematic created using CircuitLab}