Bs1 = New BindingSource With {.DataSource=Dt1}
        Bs2 = New BindingSource With {.DataSource=Dt2}

Dim a = From Elementi In Bs2 Join Elemti2 In Bs1 On _
            DirectCast(Elementi, DataRowView)("IdCompetenza") Equals DirectCast(Elemti2, DataRowView)("IdCompetenza") _
            Where DirectCast(Elemti2, DataRowView)("DescrizioneCompetenza").ToString = _
            DataGridView2.Rows(e.RowIndex).Cells(0).Value.ToString _
            Select New Livello With {.DescrizioneLivello = _
            DirectCast(Elementi, DataRowView)("DescrizioneLivello").ToString}