Keywords in Product Titles
A glance at the keywords used within any given title can provide a simple way to identify the keywords which the respective competitor is focusing on the most.
Keywords used within Seller Central's backend are, per se, not publicily available.
Sonar's ASIN Reverse Search
Additionally, Sellics's free keyword research tool Sonar can be used to identify the keywords for which any given ASIN is ranking on the first page for. These are therefore the keywords for which that ASIN should be generating most of its organic sales.
You can find Sonar within Sellics's Keyword Research feature as described here, but for the ASIN Reverse function Sonar remains more convenient.