Does a LC filter filters the voltage or the current or both?
simulate this circuit &ndash; Schematic created using CircuitLab

With a purely resistive, ideal load, the current through the load follows Ohm's Law.

V = IR

So if the magnitude of V is reduced at higher frequencies, and R is constant, I must necessarily be reduced as well, according to:

I = V/R

In a purely resistive load, there is no phase offset between voltage and current - the current follows the voltage.

This assumes an ideal circuit and is greatly oversimplified from real-world behavior.