Question

Hello Rabbi,
A French press, also called a plunger, is a utensil for making coffee using a piston with a dense filter, which pushes the coffee grounds downward and separates them from the liquid, which passes through the filter and remains above the plunger.
https://he.wikipedia.org/wiki/%D7%A4%D7%9C%D7%A0%D7%92%27%D7%A8
I wanted to ask whether this involves the prohibition of selecting/separating, and if so, whether there is a halakhic solution for it—for example, not pushing the plunger all the way down, similar to separating waste together with a bit of food from food—or whether it is completely permitted.
I seem to remember having come across a leniency allowing tea to be made on the Sabbath in a pot with a strainer, and I do not remember how that is permitted. Is that correct? And does that apply to the case of coffee as well?
Thank you in advance, and happy holiday.