Seeking guidance on implementing a code navigation plugin

Hello IntelliJ IDEA Community!

I'm trying to add a plugin for my custom Java library. I wish to achieve:

User is able to navigate off an annotated (annotation is defined in my library) method, field, or method parameter to places which are affiliated to the annotated item (which needs to inspect code and find usages)

- There can be multiple usages across different places

- Ideally should pop a menu for user to select which one to navigate to, e.g. “Find Usages” or other sub menus

- [Optional] Find usages in code on the classpath

I reckon this is similar to the Spring plugin (where you can navigate to bean definition locations in the config file), but that is not open-sourced and I struggle to find where to start. Any advice is much appreciated!