Writeback Table - Hierachy based dropdowns

Hi There, i have been working more on writeback and there seems to be a missing option (unless i just have not spotted this yet), but... 

if i am updating a particular record and there are 3 fields that can be updated, using lookups i can select anything in the 3 fields to update the records with, however this means the user can mix and match options as there is no way of using a hierarchy based filter option. and things become incorrect on that line.

what i don't want users to be able to do is make selections across the line that don't make sense, so if i select option 1 in field 1, i only want to display 3,4,5 in field 2 and option 8,9,10 in field 3 for instance. if i select option 3 in field 2 this may only then show option 10 in field 3 etc etc and so on... hopefully that makes sense and is a possibility in having this built into writeback, i think this would advance the offering even further especially when trying to force users into selections that make sense and connect correctly. 

field 1.          field2.               field3.

option1.        option3.            option8

option1.        option4.           option9

option1.        option5.          option10

option2.       option6.           option11

option2.       option7.          option12