This category is divided up into four tabs.

Segmentations

Here you'll find all the segmentations saved in your Engage environment.

Target audiences

Here you can see all your target audiences.

Labels

Under this tab are all the different labels you have in use.

Previous messages

Here you'll see all your past email send-outs, allowing you to filter for customers who have or have not received a certain email.

Every building block on these tabs can be added to the composer with the Include, Exclude, and Require buttons.

This is basically what you'll find in the filtering tool. You can access all data points in your customer database, allowing you to build logical sequences to target a precise subset of your customers. Then, as for all other building blocks, you can select Include, Exclude or Require to add this to the composer.