I am trying to figure out how to link frontend elements from the backend in the menu, without using hardcoded paths. For instance, using the following code:
Yii::$app->request->baseUrl
returns the path from the parent directory like this:
/sitename/backend/web
/sitename/frontend/web
What would be the best approach to achieve dynamic links instead?
you can use Url::to() method in yii2 which helps to generate urls dynamically. somehing like Url::to(['/controller/action', 'param'=>'value']) should help you create dynamic links between your frontend n backend menus easily. hope that helps! 
One method to achieve dynamic links in Yii2 is to make use of named routes in the URL manager. By defining named routes in your URL manager configuration, you can refer to these routes when creating URLs, which provides a more streamlined and less error-prone approach than hardcoding paths. Additionally, you can implement route aliases or URL creation methods like Url::base() to ensure consistency across your application. This ensures that links remain dynamic and adaptable to any path changes in your application structure.
have you considered using custom url managers that create unified paths for the frontend and backend? This might streamline things a bit more, especially if paths change. Curious to hear what results you achieve! also, aren’t you wondering how these changes might affect your SEO?
Hey Ryan! have u tried implementing module configuration settings in yii2? u can set up modules for front and back-end that maintain their own path config. works pretty well for shared controllers/views across both ends. just need some initial setup 
You can also utilize Yii2’s built-in alias feature to manage your paths. By defining a custom alias for your frontend and backend directories in the config file, you can reference these aliases when creating URLs. This reduces the redundancy of defining paths directly in the code and provides flexibility if you ever need to change directory structures. To implement this, you can use Yii::setAlias('@frontend', dirname(__DIR__) . '/frontend/web'); and then reference your alias with Yii::getAlias('@frontend') in your application.