I have followed Dustin Ryan's (pragmatic works) video to set up dynamic security in my cube. here is the link to the video and it's got some excellent instructions on how to do this.
https://youtu.be/NlNw3wYbh8E . The part for dynamic security is the last 15 minutes. When I Use SSMS to login to my cube impersonating a different role (my new "Dynamic" role) it says the cube does not exist. When I login impersonating a user in the dynamic security role (table driven) it gives me an error XML for Analysis parser: The 'domain\user' value of the EffectiveUserName' XML for Analysis property is not valid. (Microsoft SQL Server 2016 Analysis Services)