Multi-Dimenstional Table Library?

Hello, I am trying to create the following table/array:

A. Field1, Field2, Field3, Field4, Field5

B. Under Field1 we have
Subfield11, Subfield12, Subfield13, Subfield14, Subfield15

Under Field2, we also have
Subfield21, Subfield22, ...Subfield25

etc. until Field5

C. Under Subfields11 we have
Step111, Step112, Step113, Step114, Step115

Under Subfield12 we have
Step121, Step122, Step 123, Step124, Step125.

etc. until Subfield55

The names Field1-Field5, Subfield11-Subfield55, and Step111-Step555 can be user-defined (and may even be phrases, not single words).

Is there a Codeigniter library for this?

I already have something like this, with GUI and database saving/editing, but it was written in Core PHP, and I do not want to go that route.