Making a Custom Dashboard an Agent Dashboard will automatically filter the results so that only statistics that apply to you will show. 

In order to set this behaviour, you simply need to go to your custom dashboard and press 'Edit Dashboard', where you will see the option to 'Make this an Agent Dashboard':

Once this has been ticked, the reports will be specific to whoever is logged in and looking at this report. Please note that as this fixes the $agent/team variable, your report will need to contain this variable. This feature will not affect users that have Admin Reports permission, so you will need to share this report with your colleagues in order for them to see this behaviour.