Matte For Timewarp Question

This is probably obvious, I've worked with mattes before however not in conjunction with Timewarp.  Do I need to add a new Adjustment Layer above the Adjustment Layer the Timewarp effect is applied to, and draw the matte there?  And then select that layer as the Matte Layer in the Effects Panel?  And if so what should the layer order be?

Or do I draw it the matte on the adjustment layer where the effect resides?  Then choosing that layer as the matte layer?? 

Thanks in advance!