Quiz

Hi, I have a question bank with 400+ questions in it. I want to make that available to anyone with a teacher role (or higher) on any course page across my institution - ideally, it would just be my nursing department, for example, but let's keep it simple. Can someone break it down for me regarding the category settings for the question bank and the roles I need to give the teachers on the course pages they're creating the quiz on, please? Any info you can give me regarding any of the settings to facilitate this would be a big help.

With my admin role, I can see the question bank when I create a quiz, but it's not visible to any of the relevant teachers who might want to create a quiz from those questions. I've given them question sharer roles, and some seem to have acquired question viewer roles on related course pages from somewhere (though giving them that role doesn't appear to be an option at my level of admin - could that be an issue?). None of the guidance I've read has been particularly helpful or straightforward if I'm honest and I don't find the whole thing very intuitive. I'd appreciate it if anyone could point me to an accurate step-by-step guide or tell me where I'm going wrong. Ultimately I want to find a way of having members of each department have access to its relevant question bank wherever they are on Moodle. Thanks in advance!