Displaying Dynamic Columns in SSRS Report
Problem: How to display selected columns dynamically in SSRS reports.
Example: A report contains more than 30 fields. Some users want to see only 5 fields, some users 10 fields, and other may want to see 20 fields.
Solution: Add a Report Parameter having the values as the name of all the fields of dataset. Now set hidden expression for each column of the tabular report.

Here is the solution with an example