If you’re added as a subscriber to a share, you can log on to the Console and access the shares that the provider grants permissions to. You can log on to Analytics Database with tool of your choice and query the dataset using share.dataset.
To query data from shared datasets, use this convention - <Share_Name>.<Dataset_Name>
For example, a convention for a select query is - SELECT * FROM ShareName.DatasetName;
If the provider assigns access to a role that you are a member of then, you must use set role {role-name} command to access/query the table/view.