Level 28
What you're looking for could be a many-to-many polymorphic relation between posts, comments and tags.
posts
id - integer
comments
id - integer
tags
id - integer
name - string
taggables
tag_id - integer
taggable_id - integer
taggable_type - string
You can read further about it here https://laravel.com/docs/11.x/eloquent-relationships#many-to-many-polymorphic-relations