Is there a way to get logs stream output into a List?

I want to configure a dashboard variable with the values of this query:

{service="xxx",source="xxx"}  |= "xxx"
| pattern `<date> <time> [SYSTEM(<filter>.user)] [] <_> `
|line_format "{{.filter}}"

Expectation: to see the values of “filter” and to use it as a variable for the dashboard
As you see, I am extracting this label with the line_format. I dont know how to get the values of this label in the variable ,

apparently the result of the query shall be a list, but I dont know how to get a list instead of this logs stream.