I think you can do this with the removeprefix operator, which filters by and removes the prefix, followed by splitbefore to keep everything up to and including a delimiter. You might also need removesuffix to get rid of the delimiter.
Sorry, I'm working on my phone at the moment so haven't actually tried this.
Regards,
Mal
<$list filter="[all[shadows]prefix[$:/core/ui/ControlPanel/]removeprefix[$:/core/ui/ControlPanel/]splitbefore[/]!suffix[/]]">
</$list>