How to add different shortcodes on webpage using apply_filters(‘the_content’)?

I have different shortcodes that are generated by plugins. I have

$  content = apply_filters('the_content', $  post->post_content);  echo $  content;  

in my code to display my plugin content(for example, Contact Form 7) on the webpage.

I would like to add another shortcode plugin on the webpage. How should I accomplish it with apply_filters without using echo do_shortcodes?

Hopefully this is not an off topic question or too stupid to ask. And if possible please point me to the reference so I can learn more about it. Thank you!