App area

Groups

Collect friends into groups for a plan’s visibility.

Groups collect friends for a plan’s visibility. They are not a chat and do not change a friendship.

List of groups in PTB
Existing groups in one place.

Open a group to edit its name and the friends in it. You can then select that group under Visible to while creating a plan.

Group editor in PTB
Edit a group.

Groups & Visibility explains the exact relationship between All Friends, groups, and plan visibility.