If I understood your problem correctly:
Code:
QComboBox#cbSearchMode,
QComboBox#cbLookWhere,
QComboBox#cbSearchDirection {border: 1px solid yellow;}
QComboBox#cbSearchMode QAbstractItemView,
QComboBox#cbLookWhere QAbstractItemView,
QComboBox#cbSearchDirection QAbstractItemView {border: 1px solid yellow;}