Is it possible to set/connect first custom post's taxonomy (values) to other custom post?
Just random and basic example to understand a little better:
I've never seen anything like that in stackoverflow or in WP docs. I tried but it was too long, complicated, didn't make any sense and generated infinite errors & I thought I ask before trying again, maybe someone has been dealing with this kind of situation.
Do I just need to name taxonomies and post_meta differently and get them to query same way as post's own taxonomy and post_meta? And all same from here?
How to get other post's taxonomy/post_meta dropdown box or other types of inputs to admin edit page?
I hope that I expressed myself clearly. If there's any confusion or questions, let me know & I'll provide additional information or explain something in more depth.
You can register a taxonomy against several post types: link in the second parameter of register_taxonomy()
you can provide an array of post types. Those post types will then have the same taxonomy.