Second set of tags that use the same slug or url

I was wondering if there’s a way to create a second set of tag that can use the same slug or same url.

Normally, an example set of tag will look like this by default on the blog page:
tag1, tag2, tag3, tag4, tag5, tag6

With two set of tags, I’m trying to create something like this:
tag3, tag4 | tag1, tag2, tag5, tag6

In other words, I’m trying to get tag3 and tag4 to be in the front, and use the same slug or url.

Hello, I recently learned how to create a custom taxonomy, thanks to https://www.wpbeginner.com/wp-tutorials/create-custom-taxonomies-wordpress/
but it turns out I can’t use the same slug as the tags for a custom taxonomy. Please help.