Good morning-
This should create the filter you need:
DataView1.rowFilter = String.Format("{0}{1}{2}", _
IIf("".Equals(TextBox3.Text), "", String.Format("Title Like '*{0}*'", TextBox3.Text)), _
IIf("".Equals(TextBox3.Text) Or "".Equals(TextBox4.Text), "", " Or "), _...