Step 1: Go to app/code/core/Mage/Catalog/Model/Url.php copy this file to app/code/local/Mage/Catalog/Model/Url.php because it is core Magento file so that we have to copy that file into the app/code/local.
Step 2: Now search for the getCategoryRequestPath($category, $parentPath) around line 698 in Magento ver. 1.9.1.0
Step 3: Search if (null === $parentPath) around line 717 and comment the line as below:
/* if (null === $parentPath) { $parentPath = $this->getResource()->getCategoryParentPath($category); } elseif ($parentPath == '/'){*/ $parentPath = ''; //DO NOT Comment this line //}
Step 4: Now Go to the Magento admin and Clear Cache System->Cache Management and Reindex System->Index Management the data.
Step 5: Refresh your browser cache and navigate again now you will see only the Sub Category in Url not the Parent Category just like as http://www.abcxyz.com/test-category-level-1-3.html
Hope it helps, Thanks for reading.
Thanks