There are filters on the left hand side where you can refine the options based on your requirements.
Each employee has multiple icons assigned to them (bottom right) describing the app activity, if they worked for this organisation earlier, etc.
You can select the employee by clicking on them (they will be highlighted in green). When saving, you can decide whether you want to send these employees a message to the App which will display a notification straight away.

While testing, you might need to update the filter to Availability unfiltered, untick mobile available
and untick within range in order to get broader results.