As per the default policy, a dataset is accessible to all users who have an 'Organization Admin' or 'User' role in the organization. This policy can be overridden by specifying choosing specific users or groups with a 'User' role to have access to the dataset. The 'Organization Admin' role will always have access to all datasets.
Click the 3-dot action button on the dataset card and select Settings > Manage Permissions.
Start typing the user name or email address and select the users to whom access must be provided.
Go to 'Groups' tab and repeat the same procedure if access must be provided at the user group level.
If the user/group already has access and if you need to remove access, then uncheck the checkbox against the particular user or group.
Once all add/removes are done, click Save Changes.