To be able to use a vault, a member must be invited to Utila, either to create their own vault or join an existing one. This is a vault action that requires admin quorum approval.
You invite a member in Vault settings > Access > Members. When you invite the member you also set their role, and permissions, for that vault. The role can be changed later.
There are two types of individual members, full vault members and restricted members. Restricted members have access only to their assigned wallets, thus maintaining data privacy and segregation within a single vault.