romul / spree-advanced-taxon

You can override layout/admin.html.erb in your site-extension to change this behavior.
This fragment should be in admin layout:

    <%= tab :overview, :route => :admin %>
    <%= tab :orders, :payments, :creditcard_payments, :shipments %>
    <%= tab :products , :option_types, :properties, :prototypes, :variants, :product_properties %>
    <%= tab :reports %>
    <%= tab :configurations, :general_settings, :mail_settings, :tax_categories, :zones, :states, :gateway_configurations, :inventory_settings, :taxonomies, :taxons, :label => 'configuration' %>
    <%= tab :users %>

P.S. Probably had reason to include taxons in "Products" section...