after.php

<?php

class FooControl extends Nette\Application\UIControl
{

	public function render()
	{
		MyTemplate::registerFilters($this->template)
			->render(__DIR__ . '/control.latte');
	}

}


class BarControl extends Nette\Application\UIControl
{

	public function render()
	{
		MyTemplate::registerFilters($this->template)
			->render(__DIR__ . '/control.latte');
	}

}



class MyTemplate
{
	static function registerFilters($template)
	{
		$template->addFilter('a', ...);
		$template->addFilter('b', ...);
		$template->addFilter('c', ...);
		return $template;
	}
}

before.php

<?php

class FooControl extends Nette\Application\UIControl
{

	public function render()
	{
		$template = $this->template;
		$template->addFilter('a', ...);
		$template->addFilter('b', ...);
		$template->addFilter('c', ...);
		$template->render(__DIR__ . '/control.latte');
	}

}


class BarControl extends Nette\Application\UIControl
{

	public function render()
	{
		$template = $this->template;
		$template->addFilter('a', ...);
		$template->addFilter('b', ...);
		$template->addFilter('c', ...);
		$template->render(__DIR__ . '/control.latte');
	}

}