Sub menu's not working

my site is running at www.tiggerbird.com, however I’m having issues getting the menu structure to allow the sub items I have created appear under the 2nd levels created in the Destinations menu. Destinations menu option is set up as a Page, then under this I have sub items which are categories for UK, Asia and Europe (see attached screen shot). I’ve assigned further sub items under each of these but they do not appear as drop down options on the menu. Please help as I have tried recreating, and also changing sub items between pages and categories and am unable to get this to work at all.

Thanks in advance for your help.

Hi there,
Thanks for reaching out.
In reference to your query here, unfortunately the menu will not render items on a the third hierarchy level. Altering this would entail a bit of custom work which is beyond the scope of our support. I would recommend hiring services from Envato Studio (https://colorlib.com/out/envatostudio) on this.

I hope this helps.
Best Regards,
Support.