Hello,
First, make sure you secure all your data on the back end in SSAS. Use Windows groups and SSAS roles to properly secure the data. ProClarity products, out of the box, use Windows security to access SSAS data and will not show data that the user does not have role access to.
You will want to configure your roles in SSAS to reflect the needs of user group 1 and 2. ProClarity Pro will automatically use the currently logged on Windows user to access SSAS.
Regardless of which ProClarity product you use - Pro, Dashboard, Web Standard, security on the data is respected. There are objects in ProClarity that can be secured in ProClarity products - such as Libraries, Books and objects in the Dashboard. However, this is not data security and you need to start at SSAS. This might give you some ideas:
http://www.bing.com/search?q=role+security+ssas&src=IE-SearchBox&FORM=IE8SRC. Please let us know if you have further questions.
-Joey