Goto navigation and Edit the role based homepages
Is there a reason you are following a completely different approach for navigation and security and not following Mendix’s standard approach? In any case, if you would like to do what you have mentioned, one solution, which may not be the most ideal and elegant is as follows:
Once again, I would strongly recommend for you to understand the Mendix’s standard approach and within that see how you can accomplish your requirements rather than following this completely different approach. You might get past the first stage, but, would add to many layers in your App, which might be counter productive.
Mendix will not show the navigations for which user role does not have permission. So assign proper roles under yourmodule->security->page access. So you no need to worry about showing proper navigation menu if you have set up page access properly. (in below screenshot the director_overview page is accessed by the roles admin and directory which is configured under module security. So this navigation will not visible for Coach and participant)
For role specific home page under navigation menu you can call microflow “System.ShowHomePage” which will take care of showing role specific homepage on click of home button under navigation menu.
screenshot url: https://forum.mendix.com/file?guid=19703248369781501