Magento 2 After plugin with parameter

If you need input parameters and you also need to change output, you can use an around plugin or an after plugin:

Example using around:

public function aroundGetCategoryUrl(
    \Magento\Catalog\Helper\Category $subject,
    \Closure $proceed,
    $category
) {
   $originalResult = $proceed($category);
   
   if (...) {
      ...
      return $otherResult;
   }

   return $originalResult;
} 

Example using after:

public function afterGetCategoryUrl(
    \Magento\Catalog\Helper\Category $subject,
    $result,
    $category
) {
   if (...) {
      ...
      return $otherResult;
   }

   return $result;
} 

Just a note:

Please notice that if you are going to change an internal behaviour, a preference could be a better option that a plugin. It depends on what you are going to do.

Since Magento 2.2 it is possible to have input parameters in after plugin

namespace My\Module\Plugin;

class AuthLogger
{
    private $logger;

    public function __construct(\Psr\Log\LoggerInterface $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @param \Magento\Backend\Model\Auth $authModel
     * @param null $result
     * @param string $username
     * @return void
     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
     */
    public function afterLogin(\Magento\Backend\Model\Auth $authModel, $result, $username)
    {
        $this->logger->debug('User ' . $username . ' signed in.');
    }
}

See Magento documentation for details https://devdocs.magento.com/guides/v2.2/extension-dev-guide/plugins.html#after-methods