Wix Designer Tip: If you want to add a page to a Wix website menu more than once, you can't link to it using the link feature in the Page menu add-ons because pages already used in menu won't show up as a selection.
To work around this, just use the "Link" to link to a website address instead and choose "current window" for it to open into. You'll need to copy and paste the full URL of the page to do this, so you'll need to visit the live site to copy that URL.
I use this if a client wants to have a Page in the main Menu, but also list it in a drop down menu – so the page has two ways to get to it. Wix won't let you put a page more than once in the menu, so you can use the Website Address linking method to link to a page from the Wix website menu more than once.