Well if those dialogs still work like they used to in older LabVIEW versions, the panel itself is a real VI front panel from one of the resource files but the implementation for it is a dialog window procedure written in C(++), which is why it can not be launched from another VI diagram.
No mechanism exists to launch it.
Attached to this post is a VI that has exactly the same front panel as the Edit Events dialog from LabVIEW 2017. You could put code behind it if you wanted to use it elsewhere, but the only thing currently on the block diagram is a bunch of FP terminals.
Edit Events Dialog.vi