tfm=(TransferFunctionModel[-(20./(30.-20. (E^(-s))+0.1 s+(s^2))), ]);

delaypoles=Flatten@TransferFunctionPoles[tfm,{{-10,10},{-50,50}}];
ListPlot[Table[{Re[p],Im[p]},{p,delaypoles}],PlotMarkers->{Automatic,8}]

Manipulate[With[{approxtfm=SystemsModelDelayApproximate[tfm,order]},Row[{BodePlot[{tfm,approxtfm},Ticks->None,Frame->False,ImageSize->250][[1,1,1]],ListPlot[{Table[{Re[p],Im[p]},{p,delaypoles}],Table[{Re[p],Im[p]},{p,Flatten[TransferFunctionPoles[approxtfm]]}]},PlotMarkers->{Automatic,8},Ticks->None,ImageSize->250,PlotRange->{{-10,10},{-50,50}}]}]],{order,0,15,1},SaveDefinitions->True]