context categories/products, granular nav, context nav

Not sure what to call it, but I have the main product categories laid out horizontally at the top of the page.

I want to have only the categories and products which are specific to that main category displayed on the left.

Can I do this in admin, or is there a mod that creates a side box that does this?

While most anything that is possible can be acheived - this is not default and would require a good bit of custom code to implement and not just a couple of snippets that can be posted in a forum environment.

If this is an item that you really really must have - you can try attacking the code to add the necessary checks for which category has been selected and then what to display in the side box - a suggestion is not to use multiple nested if/else's but to employ the php "switch" function and define the cases

Or try posting in the commercial help area