如何在SSRS中创建带合并单元格的多级分组报表？

我需要将数据按客户端→计划的层级进行分组，最终报表要实现这样的布局：客户端作为第一级分组（名称仅在组顶部显示一次），每个客户端下包含多个计划二级分组，每个计划下展示对应的明细数据行。

目前我已经完成了客户端一级分组，但无法实现计划的二级分组。尝试过嵌套Tablix，却收到“详细行只能包含静态成员”的提示；使用单个Tablix时，只能做到客户端名称在每个计划分组中重复显示的效果，不符合预期。想问下这种布局必须用子报表才能实现吗？还是在单个报表里就能完成？

测试数据 #

以下是用于测试的示例SQL数据：

CREATE TABLE #t (ClientId INT, ClientName VARCHAR(250), PlanId INT, PlanName VARCHAR(250), EntryDate DATE, [User] VARCHAR(50), Invoice VARCHAR(15), [Value] DECIMAL(8,2))
INSERT INTO #t (ClientId, ClientName, PlanId, PlanName, EntryDate, [User], Invoice, [Value])
VALUES
(1,'Client One',10,'Plan Ten','3/1/24','Bob',NULL,123),
(1,'Client One',10,'Plan Ten','3/5/24','Frank',NULL,124),
(1,'Client One',10,'Plan Ten','3/28/24','Bob','1123',125),
(1,'Client One',11,'Plan Eleven','3/1/24','Joe',NULL,123),
(1,'Client One',11,'Plan Eleven','3/6/24','Joe',NULL,122),
(1,'Client One',11,'Plan Eleven','3/8/24','Frank',NULL,124),
(1,'Client One',11,'Plan Eleven','3/28/24','Joe','1124',128),
(1,'Client One',12,'Plan Twelve','3/2/24','Anna',NULL,125),
(1,'Client One',12,'Plan Twelve','3/8/24','Frank',NULL,126),
(1,'Client One',12,'Plan Twelve','3/28/24','Anna','1126',127),
(2,'Client Two',13,'Plan Thirteen','3/1/24','Frank','1125',123),
(2,'Client Two',14,'Plan Fourteen','3/1/24','Joe',NULL,123),
(2,'Client Two',14,'Plan Fourteen','3/6/24','Joe',NULL,122),
(2,'Client Two',14,'Plan Fourteen','3/8/24','Marie',NULL,124),
(2,'Client Two',14,'Plan Fourteen','3/28/24','Joe',1127,128),
(2,'Client Two',15,'Plan Fifteen','3/2/24','Anna',NULL,125),
(2,'Client Two',15,'Plan Fifteen','3/8/24','Marie',NULL,126),
(2,'Client Two',15,'Plan Fifteen','3/28/24','Anna',1128,127)

内容的提问来源于stack exchange，提问作者Digital Camel