Yeah... but doing what? Like a "filler" to me isn't specifically about an episode following an individual character. You can do that and not be "filler". If such an episode is in aid of furthering the overall plot of the show, giving the viewer wider context of how the character falls into it, showing their motivations etc. A character filler episode here is where the outcome of the episode essentially doesn't matter, and it's just done as a kind of break from the season/serial plot. Like Carol chasing rats and Daryl fixing his motorbike during those COVID era episodes of TWD.

That would be really out of place in Dark and would be just be whiplash.