Have you looked at SPCascadeDropdown? You'll need to rearrange your data a bit (to normalize it), but you should be good to go.
However, it sounds like you want to do this on a view, not a form? SPCascadeDropdowns isn't built to work outside of forms, but the logic isn't that difficult to replicate with known dropdowns.
M.
However, it sounds like you want to do this on a view, not a form? SPCascadeDropdowns isn't built to work outside of forms, but the logic isn't that difficult to replicate with known dropdowns.
M.