I have a father blog / main blog inside a multisite that has a specific taxonomy with 20+ terms inside it. i just need a list of all the terms inside that taxonomy...

i dont mind quering using WPDB but just dont know to how to write it correctly or in any other way i tried use: "switch_to_blog" but that doesnt work when quering terms

Any suggestion?
i tried the: Multisite Global Terms plugin (doesnt work)...