add 'Product Catalog' Module on Top Menu

Each user can go to their Profile and select the order in which modules appear on the top, they can also remove from the menu the modules that they don't care to have (perhaps they are not relevant to their role):

From the top right of your navigation bar go to Profile and Edit. Then in the Advanced Tab find the Layout Options:

There you can sort what you see in the Mega Menu and also move any modules you are not interested in seeing to the "Hide Modules" section.

This is a per-user setting, so every user can sort and hide as they see fit.

FrancescaS

Francesca Shiekh sums up the functionality well. There are a few additional points that may be of help:

• The admin setting ('Display Modules and Subpanels' in v12 and lower, 'Navigation Bar and Subpanels' in v13 and higher) dictates the initial tab/module layout new users see when logging into Sugar for the first time, so be sure to change the settings in this section too. 
• If you want to prescribe the settings for all users or a specific subset of your users, our Upsert Preference Enforcer plugin supports this setting as well as many others. It's helpful for instances where you don't want to have to depend on users individually making a change or to log in as each user and make the change yourself. Our plugin allows you to roll out the changes as a one-time update or you can choose to have specific settings enforced on an ongoing basis

Chris