Help with queries within queries

This is something you helped me with a while ago Ray - a site with holiday itineraries, so each itinerary had multiple days, and each day had multiple elements / activities.

I have been reworking it slightly, so now instead of a hierarchy if itinerary > days > elements it now has itinerary > segments > days > elements.

The addition of 'segments' is really for accommodation, so that it doesn't need to be added to each day.

I pretty much have it working with the segments and days displaying correctly, but I haven't gotten the elements to display.

I have attached a file and some more info below.

I'm hoping its nothing too major, and maybe just that the elements query is in the wrong place. But if it looks involved I'm happy to take this to a premium support ticket.

Thanks.