How can I make the post URL (root) different according to it's category?

Hi,

We have 2 main categories in our blog which is like Discover and its subcategories and other one is like Take Action and its subcategories. These Discover and Take Action are 2 different menu items in our main menu.

What we need is to reach these blog posts from different URLs according to it's main category.

Let's say we have these categories:

Discover
- Disc Sub Cat 1
- Disc Sub Cat 2

Take Action
- Action Sub Cat 1
- Action Sub Cat 2

Discover Post URLs will be like
http://mywebsite.com/discover/sample-discover-blog-post-1
http://mywebsite.com/discover/disc-sub-cat-1/sample-discover-blog-post-2
http://mywebsite.com/discover/disc-sub-cat-2/sample-discover-blog-post-3


Take Action Post URLs will be like
http://mywebsite.com/take-action/sample-action-blog-post-1
http://mywebsite.com/take-action/disc-sub-cat-1/sample-action-blog-post-2
http://mywebsite.com/take-action/disc-sub-cat-2/sample-action-blog-post-3

I really liked Settings - SEO options and tried to use these settings to overcome what we need but failed.
Can you recommend me a way to achive this?