"Have you tried to implement the show if region for the arrow based on the recordset that defines the second level of navigation? If you have what is the result that you are getting? If you have not applied this show region around the arrow you should give this a try by selecting the arrow and going to server behaviors > show region > show if recordset is not empty."
I tried this but this doesn't work. The result is nill.
I hope I can explain this clearly, but for example the arrow is shown at (attached to) the level_0.
If I do a show region on the underlying level_1, where also is defined whether there are records for the level_1 based on the ID of the level_0, it is not possible to do the show region in the level_0 area as it should be based on the recordset of the level_1, which is defined later in the page.