Custom User Field Filtering

Hello, and thank you for creating what appears to be a very powerful plugin. I have a couple of things I’m having difficulty trying to do with it, though. We have two plugins that we are using to manage access to pages and content: Groups and Groups File Access by itthinx. These plugins manage access via groups and capabilities. I would like to also use your plugin to hide menu items for pages that are being blocked by Groups. So, how can I verify if the currently logged-in user is associate with one (or more) group(s)?