Symfony dependency injection within a method with a variable class constructor [duplicate]

Lets assume I have the following code:

class Barman {
    private function bar($foobar) {
        // ...
        foreach($foobar as $bar) {
            $realBar = new $bar(); // how to get this via dependency injection?
            $realBar->doStuff();
        }
        // ...
    }
}

$bar is an instantiable and registered class which always implements BarInterface and therefore has a doStuff() method (checked via Reflection). The problem is that $bar looks like the following:

class MyByInterface implements BarInterface {

    public function __construct(Translator $translator, FancyService $fancyService, AnotherService $anotherService) {
        $this->translator = $translator;
        $this->fancyService = $fancyService;
        $this->anotherService = $anotherService;
    }

    public function doStuff($stuff): bool {
        $this->fancyService->exists($stuff);
    }

}

So $bar is usually created by Symfonys dependency injection container and it will not be easy to get all those constructor parameters needed in a dynamic loop.

Long story short: What is the correct way to get a usually dependency injected object in such a dynamic loop (with Symfony V4 / V5)?