So you are wanting to change the location of your employees within the job tab of their profile, but your business locations are not showing up as selectable in the drop down?

This is due to having Location Bookings enabled within the module settings as seen below:

With location bookings enabled, this allows your users to book their working location each day from their dashboard as seen below:

If you are wanting to change their employee working location yourself, you will need to disable the location booking setting by following the pathway: Configure > Settings > Modules.