Fields for the seo extension are in the hivepress settings under listings. Does the meta description refer to listings or to the content pages? In case of use of yoast, where these fields are also present, is hivepress seo extension or yoast ruling?
This depends on the settings tab, if it’s Listings then this is the meta description format for listings. You can still use Yoast for more precise description if required (but description format in our SEO extension accepts attribute placeholders, while Yoast would require some extra setup). The HivePress SEO extension is not based on Yoast, but these 2 plugins can work together, e.g. if you use Yoast for meta description while using HivePress SEO for setting up Schema.
Assuming this is for listing, what happens if the meta in yoast is also filled in? Which one is found by google?
Both would be added to the site HTML, please choose only one of these options.