You can hack it using the code below. Or, if you have our source code, you can dig through OnScrollTipFeedback in \Windows\Grid.Grouping.Windows\Src\Controls\GridTableControl.cs to see how it prepares that string.
private void TableControl_ScrollTipFeedback(object sender, Syncfusion.Windows.Forms.ScrollTipFeedbackEventArgs e)
{
int i = e.Text.IndexOf("Items");
if(i > -1 && e.Text.StartsWith("Category") )
{
e.Text = e.Text.Substring(i + 6);
e.Size = new Size(200, 20);
}
else
e.Text = " AddNewRow ";
Element el = this.gridGroupingControl1.Table.NestedDisplayElements.GetItemAtYAmount(e.Value);
if(el is GridRecordRow)
{
DataRowView drv = el.GetData() as DataRowView;
if (drv != null && drv.Row.Table.Columns.IndexOf("Name") > -1)
{
e.Text = drv["Name"].ToString();
e.Size = new Size(200, 20);
}
}
}