Community → Tiers holds the list of tiers. A tier is a label: it has no price, no checkout and no link to payments.
Fields
Label (up to 120), Slug (the key, up to 64, letters, digits and hyphens), Description (up to 500) and Sort order. The slug cannot be changed after saving, because members and spaces store it. There are no tiers until you create them.
Deleting
A tier still held by members or used as a space gate cannot be deleted: the message says how many members and gates use it. Move them first.
Viewing needs the view-members permission; New, Edit and Delete need the community settings permission and a plan with community management.