Hello,
There is something I don’t understand with parenting a container inside a “OP Viewer” with a video output :
my goal is to display the Nul TOP renamed video_out inside the white bordered rectangle on left side of the op viewer (named interface).
Inside the op viewer there is a container called preview, on Background TOP, I wrote “parent().video_out” but nothing occurs on the container :
It should display the Null TOP inside 
thanks in advance
ok, finally i’ve founded how to do so : instead of parent().video_out it should be : ../video_out
hope it could help other 
great that you figured that out. Generally hierarchy in networks follows how this is done in windows or on unix with a ./ meaning one level down and a ../ meaning one level up.
parent() on the other hand is a python member returning a reference to the next up component. You need to switch the parameter into python mode for this to work. But also here, to get to the operator inside, you could use me followed by a reference to the operator: me.op('video_out') or op('./video_out')
A bit more information can be found here:
Best
Markus
