California Love does not feature Nate Dogg. The song is performed by 2Pac and Dr. Dre, with Roger Troutman on the talkbox. Nate Dogg, known for his distinctive vocals and laid-back style, collaborated with 2Pac and Dr. Dre on numerous other tracks, but California Love is not one of them.
Nate Dogg Knowledge Knockout: 31 Questions to Determine Your Mastery