In JomSocial 3, all of the templates paramaters for frontpage are removed because these blocks are turned into modules that can be published anywhere on the site
Template parameters allow you to configure certain parts of the site (primarily the Frontpage) and decide which boxes will be shown, and when. The configurable options are listed below and can be accessed from every JomSocial Template configuration page
Backend -> Components -> JomSocial -> Templates -> Your Template
and from the layout configuration page
Backend -> Components -> JomSocial -> Configuration -> Layout