WhatsApp said that it is working to bring the ability to login from multi accounts from the same device in a future update, as per Wabetainfo. With the feature, one can switch between several accounts.
As per the screenshot, WhatsApp is working on a menu that will allow users to select which account they want to log into. The additional account will be stored on the device until one decides to log out of the account.
Without having to install and configure WhatsApp separately on each device for creating a new account, users can use one device. The new feature will endure privacy and easy management of notifications.