a way to know what segment of event DOP is applied to ?

Hi,

In the right-top corner, you can see the DOP (wave-form) symbol, if you apply DOP to any part of the file, so even if you use Range Selection Tool and apply the DOP just for a range of it. But you can’t see, to which range exactly and you even can’t re-select the range again.

This is a known design issue.