Each pipeline has its own access, set under Who can use it on the pipeline in Settings → Pipelines:
- Edit: everything, including adding, changing and deleting its deals;
- View: see them only. They can open the deals and read everything, but can't move them between stages, win or lose them, or change anything (fields, tags, followers, contacts, notes, files or tasks on them). The board says View only — you can open opportunities but not move or change them.
- No access: the pipeline is hidden from them everywhere: lists, boards, searches, exports and the API.
Setting it
Set Everyone else (the default, Edit to start with), the Staff role, and, for a person who needs something different, their own level (or Use the default). A person's own level wins over their role's.
Owners and managers, and your agency's own people, always have full access to every pipeline; their level can't be lowered.
Nobody is cut off from their own deals
You can't set someone (or their role) to No access on a pipeline while they own open deals in it. The message names them: give their deals to someone else first.
How it fits with other switches
Pipeline access works on top of the person's role and switches. Someone with Only contacts assigned to them sees, in the pipelines they can reach, only the deals they own or follow. Can't delete opportunities and Can't export opportunities still apply on pipelines they can edit.