Grant access to a workspace

 https://support.atlassian.com/bitbucket-cloud/docs/grant-access-to-a-workspace/

Group access on future repositories

When you create a repository in a workspace with existing user groups, Bitbucket determines if the workspace has any groups with the Default Access permissions of Read, Write, or Admin. If it does, Bitbucket adds those groups to the new repository with the default permission. If you specify None for the default permissions, Bitbucket ignores that group and doesn't add it.

To update the group permissions for only one repository, you can do so from the User and group access page of the repository settings.