Delphi and Oracle - Cannot access field "TRANSACTIONS" in a filter

Question

when trying to access the value of a field it does not allow me to obtain it, I am doing it in OnFiltered of the DataSet.

procedure TFrm_Transactions.qry_personal_trxsFilterRecord(DataSet: TDataSet; var Accept: Boolean);
var
  vprs, vtrxs: string;
begin
  if qry_personal_trxs.FindField('TRANSACTIONS') = nil then
    accept := True
  else
  begin
    vprs := DataSet.FieldByName('PERSONAL').AsString;
    vtrxs := DataSet.FieldByName('TRANSACTIONS').AsString;
    accept := (vprs = vPersonal) and (pos(',' + vTransaction + ',', vtrxs) > 0);
  end;
end;