@daniel-alonso could be that your page title is not within the WP loop. Appending /create to the groups directory URI will help you get to the Groups Create page. e.g. example.com/groups to example.com/groups/create
Or, if you’re feeling adventurous, you can add the code to your My Account section of the WP Toolbar https://buddypress.trac.wordpress.org/ticket/1838