With your Rockettheme template, you could use these steps...its a few steps, but I think it will accomplish what you want.
In short, you're going to create another main menu for use in your iframe, which you can then display differently with template configuration or template assignment.:
- Create a new "hidden" menu that is an alias of your link to jomsocial, but don't publish the menu anywhere - it just has to exist and be published so that the itemid is valid and your jomsocial component can be reached with it.
- From Admin, copy or create another new menu and call it something like "mainmenu_4iframe"
- On that menu, add all the menu options that you want available from the iframe as menu aliases. This then runs those menu items, but with a different menu Itemid (this is critical)
- From your template configuration, make Menu Settings overrides for the Hidden menu item and the mainmenu_4iframe to make your template appear differently if they go to jomSocal from that link (which is the one they would use in the iframe SRC attribute)
- If changing the default template for the menu items doesn't work or is too much trouble, you could instead, have a basic template like 'beez' or something and assign that template to your new menu items.
I think that covers it, it's been awhile since I've done it, but I think anything I've overlooked can be quickly figured out. - Good Luck