我能够找到答案:

首先使用名称节点创建模板变量，并设置type = constant

First create template variable with name node and set type = constant

使用 Url http://servername:3000/dashboard/db/dashboard?refresh=10s&var-node=hanoi

在查询中:使用where子句，如下所示:

In Query: use where clause as shown below:

WHERE "system_id" =~ /^$node$/