Do SonarX2 a solo mode as Cubase?

What do you mean? X2 has 3 solo modes. 

No. I ask whether it is the "solo" to switch between tracks.

I'm a little confused by the question.

Yes you can solo tracks, you can also "Dim" solo which allows other tracks to playback at a reduced volume, there's also "exclusive" solo which means only one track can be soloed at a time, and also solo override meaning that the track or buss will always be soloed (except when muted).

I should imagine that must cover just about all solo requirements.

  That would be the Exclusive Solo. In the Mix Module you engage Exclusive Solo there. There is also Dim Solo. This does what regular solo does except it lowers the other track but does not mute them. Exclusive Solo will switch to the next track soloed and unsolo the last track. Regular solo will allow soloing more than one track.   

So what exactly is Cubase's solo mode?