Business Pro: Fixed Header

In newer versions of Business Pro (1.0.5 and higher) it is possible to enable a fixed header from the Customizer. 

Navigate to Appearance → Customize → Theme Settings → Site Layout and check the Enable fixed header option:

Older versions will need to enable theme support for a fixed header by adding the following line of code to the functions.php file:

add_theme_support( 'fixed-header' );