Dashbord view classification ( variables )

Hi ,
I need help concerning the view of grafana dashbord , i work with blackbox exporter and i want to classify my supervised URLs according to the domain .
My current dashbord displays informations according to jobs and targets , but i want to gather my URLs by domain .
for example i have google.com as my domain and i have plenty of subdomains under google.com so i want to have as variable google.com and put my domains under it so if i want only to display the subdomains of google.com i will be able to do that .
Thank you