I am creating a business rule to auto-populates the field with the current user contact for custom field Owner, but I am not able to find out what should be the action for this and also not able to see the current user option. Please see the screenshot below
Not possible with rules on classic pages. Best option would be to set it as the default for that column in the object. Select the object and choose the Owner column and set Current User Contact for default value. Otherwise, you'd need to get current user and populate via code in the onEntityInitialized - make sure the page is in add mode.
