How to get unspents for a specified bitcoin address? I want to access unspent data of a specific bitcoin address.

I am trying this command

bitcoin-cli -regtest listunspent "some bitcoin address"

But I am always getting an empty list. I am using local bitcoind server on windows 7.

What should I do or use any function for getting desired output ?
listunspent only displays information about addresses which are currently part of your wallet. Bitcoin Core does not maintain indexes of unspent outputs for addresses you do not own, and will simply return a blank set if you attempt to query for them.