The QGraphicsView is a window into a world (the QGraphicsScene). What you're asking would be like saying that it's raining when I look outside my windows, but can I have it only rain when I look through one of them?!
However, you can change the curtains(!), so override the function of the QGraphicsView, rather than the QGraphicsScene. I suggest using this: -
QGraphicsView::drawForeground(QPainter *, const QRectF &);
Apply this just to the view you want to change. With two views, you'll need a flag to set which of the views you want to apply this to. For example: -
void MyGraphicsView::drawForeground(QPainter* painter, const QRectF& rect)
{
QGrahicsView::drawForeground(painter, rect);
if(m_bDrawGrid)
DrawGrid();
}