If you want to have different menu on various sites, for example: On front page menu with anchors to sections and different for sub-pages, then you can use for this plugin Menu Swapper.
You can find plugin here.
How to use it
New theme location
After you activated plugin, you now have to go to Settings → Menu Swapper. There you will have to follow instructions and create new “theme location”.
Create your menu
Next we move to Appearance → Menus and create new menu, and assign it to location that we have created in previous step. Scroll to Theme locations and mark menu to use new theme location.
Assign your custom menu
When we have everything prepared, time to swap you default menu with that prepared in previous steps.
To do we go to page that we wish to have with special menu & edit it.
On right side of edit screen you will find box named Menu Swapper. In it:
- In option Replace this Theme Location you choose Site Navigation
- In option With this Theme Location you chose theme location that we created in first step.
Now you should see different menu for this page.