#5475 "Rule form: pick the host, then its part; metrics that part reports; a link to groups; a preview of the metric", from the operator's review of the New rule page: hosts and their parts shared one long picker. - Host agent rules pick a Host, then a Part: "The whole host", then its mounts, CPU cores, disks, interfaces and sensors under a heading each, cores in number order. A part that reports nothing a rule can watch (an interface's traffic) isn't offered. - The Metric list holds what the picked resource reports, in catalog order. - Under it, a preview: the reading now, and the last 24 h low to high with an hourly sparkline drawn from zero (UI ruling 8), read from one series. - The group picker links to Ansible > Inventory to make a group, in a new tab, and re-reads the groups when the tab comes back into view. - Picking a host or part swaps the pickers alone (/alerts/api/rule_target); picking a metric swaps the preview (/alerts/api/metric_preview). - A rule's own resource and metric stay on offer after they go quiet. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>