Show/Hide Pattern Browser ⌥⇧B
Show or hide the Pattern Browser. A large collection of starter patterns.
Load and save patterns in Step Sequencer in Logic Pro — Apple Support
Step Sequencer includes a Pattern Browser where you can choose and save patterns and templates. The Pattern Browser contains a variety of premade patterns for drums, bass, keys, and other instrument categories that you can use in your projects. The Pattern Browser also features templates, which include pattern, row, and step settings but with an empty step grid, that you can use as as a starting point for creating patterns.