issue while working with dyunamic column group

Hi , greeting for the Day !!

I am developing the matrix report in SSRS, in this I have created the Rown group based on branch (e.g. Mechanical, Coputer Sc. etc) and a column group based on Subject Code (e.g CE01, CE02 CE03 Cor etc).

now the problem is while running the report column group displayed the all branches subject , not generating the subject on the basis of the row group.

I want like if first branch is CE than column group only displayy the CE subjects in column group and while the group change the respective subject should be displayed in the column group

please help

thanks in advance