When you collapse a set, you can select the set and use any channel strips or busses at the set level but cannot select or play patches in the set while in Edit mode.
In the Patch List, click the disclosure triangle for the set.
You can uncollapse the set by clicking its disclosure triangle again. Collapsing a set has no effect on whether you can select patches in the set in Perform mode.
For information about creating and using sets, see Work with sets overview.