I want to use same keywords for multiple ad groups with different landing page URLs within the same adwords account.
Sounds like you are looking to test multiple landing pages against the same set of keywords - is this correct? If so, apply different ad texts - one for each unique landing page - to the same keywords in one ad group.
Google maintains a high standard for our user experience and the quality of our advertising. In order to preserve the quality and diversity of ads running on Google, we do not allow advertisers or affiliates to have any of the following:
Multiple AdWords accounts.
Ads across multiple accounts for the same or similar businesses.
Ads across multiple accounts triggered by the same or similar keywords.
Currently, you may only have a single AdWords account. However, your account may contain multiple Ad Groups and ads triggered by the same or similar keywords.
As already mentioned, if you want to test which is better you should have the keyword in 1 adgroup with multiple versions of ad copy pointing to the different URLs.
If you use keyword-level URL tracking, you're in a tough spot though. Because in that situation, you won't be able to test multiple landing pages at the same time (because the URL is set at keyword level, not at the ad level where it would rotate)