The apps aren’t there yet for this.
https://browse.feddit.de/ is a good way to search through all communities across all instances though. I’d search there, subscribe in the browser, then you’ll see it in your app (with a refresh obviously).
It will get easier as time goes on and lemmy (and the apps for it) get more developed.
London Metropolitan Police (Met) have stopped incel groups and their 39 separate terrorist plots, which were to attack the London Pride Event, Members of Parliament (MPs) and more (landmark sites as mentioned in the article).