The answer is mostly everywhere. To further nail the point Sherwin and John made yesterday, that the majority of Bellevue citizens support Sound Transit 2 and East Link, I made a map specifically showing only Bellevue precinct level results. The current East Link Preferred Alignment is also shown with both C9T and C11A options.
While support and opposition is spread throughout the city, the map makes it easy to see what each neighborhood was thinking. 57% of votes from the two Surrey Downs precincts rejected ST2. Compare that to the majority of their neighbors in nearby Enatai, Bellecrest and Downtown who voted to approve ST2 and also the 56% citywide. Residents in precincts along the BNSF and Bel-Red corridor also had high approval.