Multi Columns filtered gridview

Question

frmInnovationsGridView.InnovationsTable.Columns[17].HeaderText.ToString() + " = " + '1';

I have a telerik RadGridView .

I have a filtere code that works like charm for only one column. What I need is that i want my code to filter 2 or 3  columns at the same time,

 

Here is my code:

 

bs.DataSource = frmInnovationsGridView.InnovationsTable.DataSource;
bs.Filter = frmInnovationsGridView.InnovationsTable.Columns[25].HeaderText.ToString() + " = " + '1';
frmInnovationsGridView.InnovationsTable.DataSource = bs.DataSource;

 I want to add another column filter as following;

 

frmInnovationsGridView.InnovationsTable.Columns[17].HeaderText.ToString() + " = " + '1';

 an a third column filter as following;

 

frmInnovationsGridView.InnovationsTable.Columns[17].HeaderText.ToString() + " = " + int.Parse(EmployeeID.Text);

 but EmployeeID.Text value will come from frmMain.Employee.Text

 

 

How can I do this

Thanks