Fields added via options pages are all saved and loaded in via ‘option’ as opposed to page id. As such, the only way to have two options pages with unique data is to make them each have unique slugs.
https://www.advancedcustomfields.com/resources/register-multiple-options-pages/
Once you’ve changed the slugs for the pages, you won’t be able to see the data any longer – so do keep it open in a tab or just c&p somewhere if it’s important to keep a record of it before changing.
As to referencing this data, outside of having an if statement to check the post type and output the relevant options depending on the outcome, if you put the relevant post type at the beginning / end of the field name, you could reference this using the WordPress get_post_type function.
get_field( get_post_type($post) . '_description', 'options' );
