select a.field0047,

case when a.处理时长<30 then '<30天'

when a.处理时长>30 AND a.处理时长<=60 then '30~60天'

when a.处理时长>60 AND a.处理时长<=90 then '60~90天'

when a.处理时长>90 AND a.处理时长<=180 then '90~180天'

when a.处理时长>180 then '>180天'

else null end as 时长段,

count(*) as num

from (

SELECT 

field0047,

DATEDIFF(day, field0012, GETDATE()) AS 处理时长

FROM formmain_1141

WHERE finishedflag = '0'

) a

group by a.field0047,

case when a.处理时长<30 then '<30天'

when a.处理时长>30 AND a.处理时长<=60 then '30~60天'

when a.处理时长>60 AND a.处理时长<=90 then '60~90天'

when a.处理时长>90 AND a.处理时长<=180 then '90~180天'

when a.处理时长>180 then '>180天'

else null end

你得在sql里分组求和，或者建多个数据集用过滤条件过滤

参考这个，自定义按段分组

https://help.fanruan.com/finereport/doc-view-318.html