Global variable in Grafana 10

How to create a global variable that can be used in other Dashboards?
In my Project ,I hava many Dashboards.
In every Dashboard ,I need define some same variables,such as dashboard for serviceA,dashboard for serviceB and so on.They all need the variable (total_count:count(go_info{job=‘linux’,service=‘${service_name}’}) .
Now I have to define this variable in every dashboard.Is there any way to cover my needs?