The search below would limit an "alert" tag to the "host" field.
tag::host=alert
The search does the following:
It uses tag syntax to filter events by tags. Tags are custom labels that can be applied to fields or field values to provide additional context or meaning for your data.
It specifies tag::host=alert as the tag filter. This means that it will only return events that have an "alert" tag applied to their host field or host field value.
It uses an equal sign (=) to indicate an exact match between the tag and the field or field value.