SMART datagrid v.1 > Classes > ColumnGroup
Return the last ValueColumn object among the displayed child columns. If horizontal layout, the rightmost, and if vertical, the downmost ValueColumn will be the last one. If visibleCount is 0, it will return null.
var group = grid.columnByName('group1');
var column = group.last();
if (column) {
column.setVisible(false);
}