JSON expansion in Power Query M

JSONexpand.m

= List.Generate(
	()=> [
		can_expand=true, 
		level	=1, 
		input	=json, 
		output	=[level.0=Record.FieldNames(json){0}]
		], 
	each [can_expand], 
	each [
		can_expand =Record.FieldValues([input]){0} is record, 
		level	=[level]+1, 
		input	=Record.FieldValues([input]){0}, 
		output	=[output]&(   if   Record.FieldValues(input){0} is record
				    then   Record.AddField([],"level."&Number.ToText([level]),Record.FieldNames(input){0})
				    else   input
                                )
		],
	each [output])