Is there a way to find the parent block of a nested block, programatically?
rs.BlockContainers(block_name)
https://developer.rhino3d.com/api/RhinoScriptSyntax/#block-BlockContainers
If it returns None, the block is at top-level (no parent).
Yeah, I just made a few tests with all the block methods in rhinoscriptsyntax 
it gets a list of all the parents of that particular block. If it is nested multiple times list[-1] gives the greatest grandparent.
I need to figure out if working inside the block is powerful enough or I should consider exploding instead.