Tips for Data Model

I can’t quite seem to get the data model down for a fairly simple set
of data.

The data is:

Framework --> Strand --> Level --> Benchmark

It would be simple enough if there were only three levels but since
there are four I can’t use straight has_many xyz :through clause.

The end goal is to have users be able to select a framework, then a
strand, then a level, then a benchmark.

Any help would be appreciated.

I’m not sure I understand why the number of levels (3, 4, or 104) is an
issue. So, perhaps I’m not understanding your question. But why not:

class Framework < ActiveRecord::Base
has_many :strands, :dependent => :destroy

class Strand < ActiveRecord::Base
belongs_to :framework
has_many :levels, :dependent => :destroy

class Level < ActiveRecord::Base
belongs_to :strand
has_many :benchmarks, :dependent => :destroy

class Benchmark < ActiveRecord::Base
belongs_to :level