As an Administrator, you are able to enable Whole of Market Mode for users.
Navigate to Setup at the top right of the screen:
Type Users into the Quick Find box
Click Users under Users:
Click into the user you would like to allocate the permission to:
Once within the User account, scroll down to Additional Information:
Tick the Whole of Market Mode Permission box:
The user can now override the use of a segment and complete Whole of Market research.