Hello,

Unfortunately, there is no method to expand all if you have more than 1 group levels.
I think it is more easier if you handle this in client side.
Please see my attached code. I am using on button click.

  function Button1_onclick() {
            var grid = ISGetObject("WebGrid1");
            var currentRow = grid.GetSelectedObject().GetRowObject(); 
            currentRow.ExpandGroupRow(); // expand group row
            for (var i = 0; i < currentRow.GetGroupChildRows().length; i++) {
                currentRow.GetGroupChildRows()[i].ExpandGroupRow();
            }
            return true;
                       
        }

Regards,
Handy 

For my case, that can't work. On my button click function row is inserted in the database. That is why I use grid.SendCustomRequest(); and  WebGrid1_InitializePostBack event handler so that datasource is refreshed with new row.

Also, your approach to expanding is top to bottom. Your code gets first group and expands it, and then expands all the children. I want to expand only groups and subgroups that lead to the new row (the one that was inserted on button click).

However, I found another way.

On the server-side in InitializeRow event handler, I first detect positions of the coresponding groups and invoke function on the client-side with those group positions.

protected void WebGrid1_InitializeRow(object sender, RowEventArgs e)
        {
            if (e.Row.Type == ISNet.WebUI.WebGrid.RowType.Record)
            {
                if (e.Row.Table.IsRootTable)
                {
                    int? newSastanakID = ConvertSafeNullable.ToInt(Session["NoviSastanak"]);
                    if (newSastanakID.HasValue && e.Row.KeyValue.ToString() == newSastanakID.Value.ToString())
                    {
                        var rootRow = e.Row.GetRootRow();
                        bool found = false;
                        int rootLevel = 0;
                        int subLevel = 0;
                        int subsublevel = 0;
                        foreach (WebGridRow rr in rootRow.Children)
                        {
                            foreach (WebGridRow rr2 in rr.Children)
                            {
                                if (rr2.Cells[0].Text == e.Row.Parent.Cells[0].Text)
                                {
                                    rootLevel = rootRow.Position;
                                    subLevel = rr.Position;
                                    subsublevel = rr2.Position;
                                    found = true;
                                    break;
                                }
                            }
                            if (found)
                            {
                                break;
                            }
                        }
                        WebGrid1.ClientAction.InvokeScript("ExpandToRow", new ISNet.WebUI.FunctionParameter[] { new ISNet.WebUI.FunctionParameter(rootLevel.ToString(), "int"), new ISNet.WebUI.FunctionParameter(subLevel.ToString(), "int"), new ISNet.WebUI.FunctionParameter(subsublevel.ToString(), "int") });
                        Session["NoviSastanak"] = null;
                    }
                }
                
            }
}

The client-side function looks like this:

 function ExpandToRow(rootLevel, subLevel, subsubLevel) {
            var grid = ISGetObject("WebGrid1");
            var rootRow = grid.RootTable.GetRowByGroup(0, rootLevel);
            rootRow.ExpandGroupRow();
            var subRow = rootRow.GetGroupChildRows()[subLevel];
            subRow.ExpandGroupRow();
            subRow.GetGroupChildRows()[subsubLevel].ExpandGroupRow();
            return;
        }

This way, only the groups that row is member of, are expanded.