Add an additional navigation bar above the header for language, currency and custom menu
Add the toolbar block in the header settings to provide easy access to for language and currency drop-downs. You can also add a custom secondary menu into the toolbar:
Customize the second menu in your Shopify Navigation editor:
The toolbar is displayed inside the mobile navigation drawer which keeps your main header clean and doesn't occupy screen space.
The second menu is displayed below the main navigation menu:
Toolbar features can be toggled for desktop and mobile
Language and currency drop-downs are placed at the bottom of the mobile navigation drawer: