enclosing_method(var1,var2) do
    enclosing_method(var3,var4) do
        get_tree # This method should return an array of it's enclosing methods
        # e.g. [get_tree, enclosing_method, enclosing_method, main]
    end
end

class Myclass
    @@all_instances
    def initialize
        @parents = get_tree # method that will return
        # all of the containing instances / anythings
        @content = yield
        @@all_instances << self
    end
    attr_reader :content
    attr_reader :parents
end
Myclass.new do
    Myclass.new do
        get_tree # => [Myclass, Myclass, <main>]
    end
end

> Myclass.all_instances[0].parents # => [<main>]
> Myclass.all_instances[1].parents # => [Myclass, <main>]