You can choose which fields to display in the Employee directory by ticking and un-ticking the relevant boxes in:

Administration> Company> Settings> Display Settings

Under the 'Directory' section, you will see the options outlined below. 

Any fields which are ticked will be shown; those which are not ticked will not. Please note, employee name is not an optional field and will always be shown.

Custom fields can be selected, re-named and edited. To view how to edit this, click here.

As you can see from the example below and the checked fields above, only the employee's Job title, image, department, manager, site, telephone, mobile (if entered), email and any social recognition (in this instance, none) awards are shown on the directory.