I use this code on the Search button of the frmGrid to filter all the records with the same position.
Dim aFind As String = InputBox("Enter a Position", "Filter Employees Position")
'Filter
DataSet11.Employee.DefaultView.RowFilter = "empposition like '" & aFind & "%'"
DataGrid1.DataSource = DataSet11.Employee
On the Input Box I type: "Clerk" and all records with this position display.
But if want to navigate records using "<<" and ">>" doesn't work. Try to see the file attached with this thread for you to understand this.
I tried downloading your zip file and didn't want to open. However back to basics, remember a datagrid only reflects the underlying data in your dataset. Navigating the data means moving the Datarow pointer up and down. Therefore to move forward one, set your datarow value +1, move it back set it it value -1.
The current value will reflect the data it is on.
I feel sure there is a sample program prvided to do just that, check that area in Visual Studio.