I'm not sure this would require changes to the dissectors.
I would /think/ that this could be done similar to how the Expert Info system highlights the (tree) path down to the item to which the expert info is attached. That is, it could be done in the proto_tree_add*() calls by, for example:
- Checking if the field being added was part of the display filter
- If so then highlighting the path back to the root of the tree (like the expert info calls do)
I don't know, however, how you could visually distinguish expert info's from the "here is(are) your field(s)" highlights.