When a voice has multiple keymaps spread across different rows, you have an option to change the rows using the keys mapped in the vertical green column (can be moved around and resized by mouse). However you can also now assign a specific MIDI CC from your modulation wheel (click the button and select the CC number) and then change rows by moving that.
Just note that the CC used for this will no longer affect any modulation defined in the MODULATORS pane.