ClickStack Demo Day (2026-08-21) - Dependent dashboard variables and macros

Dashboard filter definitions can now reference other variables in their WHERE clause, so one drop-down scopes another. Selecting a service name narrows the severity drop-down to the values that exist for that service. Options are still queried when a referenced variable has nothing selected yet. Use $__filters or $__conditionalAll if you want values to populate in that state; a bare expression IN ($var) returns nothing until $var has a selection, and a tooltip explains why. Macros also expand variables passed as arguments, so $__timeFilter($TimeColumn) works. Both the external API v2 and the MCP server understand variables, which means Terraform does too. An agent can build a dashboard with variable and broadcast filters, dependent drop-downs, and tiles that reference those variables directly or through macros. Part of the ClickStack Demo Day series. See the full post at https://clickhouse.com/docs/use-cases/observability/clickstack/demo-days/2026/2026-08-21