I want to put a checkbox in ui-grid column header to group row according to that column. I don't know how to add extra input field to column header. What would be the approach to do this ?
The headerCellTemplate property on the columnDef should let you control what you want in the header. I'd also look at the menu item that grouping adds for grouping a column, you'd want to make the same call to group and ungroup the individual columns.