hey Kate,
So the first place where you have to go is:
components/com_hotspots/views/all/tmpl/default.php
There you will see stuff like this:
$pane =& JPane::getInstance( 'tabs', array('startOffset'=>0));
echo $pane->startPane( 'pane' );
echo $pane->startPanel( JText::_( 'Map' ), 'base' );
This are joomla functions that create those tabs.
This function hotspotsUtils::hs_showcategories(); give you an array with your categories.
So you may want to make a foreach and create a new tab for each of the categories in the array.
But this is the easy part.
If you look further down in the file yo uwill see <div id=map_cont"...<div id="map_canvas".... so here is where the magic starts
We replace thsoe divs with the map. So each tab you will have to make new div and then with js load different maps.
You will also have to hack the functions in media/com_hotspots/js/hotspots.js (not exactly sure for the right path to this file). And make it so that for each of those the component loads your markers.
The biggest problem with what you want to do is I believe performance. The content of the tabs is not loaded dinamically, but created while the page loads. So if you have 3 maps, then the browser will have to do more things and this will most probably show bad performance for the end user.
