Dynamic drop-down lists

Hi all, I'd like to have dynamic dropdown lists in cells G5:G10 of the attached file.

Section 1 of the mock-up represents the reference data.
Section 2 is where the user enters data. The user enters a Class Code in column F and then the required Data Validation (DV) list should appear when a cell is selected in column G.
Section 3 contains the DV lists and works fine: it captures the used classes and then based on those selected, builds a set of dynamic lists. It would be great to have a single 2D dynamic array here, but given the different row dimensions, I don't think it's possible.

I'm a little stuck on the last step, finding a formula to apply DV to G5:G10. All suggestions appreciated and TIA...