The Solo buttons of all swiped tracks switch to the same state.
Press and hold Shift while the Solo button in the control bar is active, then click the names of the tracks you want to solo.
In Logic Pro, click the Clear/Recall Solo button in the area above the track headers.
To resolo all previously soloed tracks, click the Solo button above the track headers again.
Download the guides:
Logic Pro User Guide: PDF
Logic Pro Effects: PDF