Filter label_value function with query on value

[f1outsourcing]

This question has already been asked, but instead a work around has been given.

This generates output
label_values(libvirt_domain_state_code{instance=~"$instance"} , domain)

This is a valid prometheus query that generates output
libvirt_domain_state_code{instance=~"xxx"} == 1

However this does not work
label_values(libvirt_domain_state_code{instance=~"$instance"}==1 , domain)

How to filter result of label_value?

Hi, we are running a platform of jobs, there are one or more tasks in single job, so we are exporting metrics like: task_mem_usage{"job"="a", "task_name"="1"} 2 task_mem_usage{"job"="a", "task_name"="2"} 3 task_mem_usage{"job"="b", "task_name"="1"} 2 we want users can see both job-level metrics and task-level metrics. So we defined two variables: job and task, the query for job is easy: label_values(task_mem_usage, job). But if task is defined as label_values(task_mem_usage, task_name), it wo…