Edit the rebar constraints to adjust the bar lengths or distances to the concrete faces of multiple rebar sets at the same time.
For a selected bar handle on one of the sets, the corresponding bar handles are highlighted for all the other sets in the selection.
When you select a new constraint target - which could be a concrete face or a bar segment or plane, the selection is applied to all the corresponding bar handles:
Drag the shape handle to move all the corresponding bar handles by the same transformation: