The acedNEntSelP() function is similar to acedEntSel(), except that it passes two additional result arguments to facilitate the handling of entities that are nested within block references.
Another difference between acedNEntSelP() and acedEntSel() is that when the user responds to an acedNEntSelP() call by selecting a complex entity, acedNEntSelP() returns the selected subentity and not the complex entity's header as acedEntSel() does. For example, when the user selects a polyline, acedNEntSelP() returns a vertex subentity instead of the polyline header. To retrieve the polyline header, the application must use acdbEntNext() to walk forward to the Seqend subentity and obtain the name of the header from the Seqend subentity's -2 group. This is true also when the user selects attributes in a nested block reference and when the pick point is specified in the acedNEntSelP() call.