How to group more than one sub table items in crystal report

Hi All
 
My doubt is regarding with grouping in crystal report. I have four tables a,b,c,d The primary key of table a is in b,c, and d .I want to create a report of this tables .I want to display details like
 
Table a's details
b_Items
details in b corresponding to a's id
c-Equipment
details in c corresponding to a's id
d-Expense
details in d corresponding to a's id
 
I used group concept .Grouped by using a's Id.but there is only one detail section coming while grouping .if i placed heading (b-items) section in the header and "details in b corresponding to a's id" in the detail section .How could i place remaining things in my report.i mean c-Equipment,d-Expense.there may be more than one or two items in each section of b_items,c-Equipment,d-expense.How to list Sub items below the main head one another. Please give a solution to solve this.
 
Thanks in Advance
Amrutha