Huge Performance Improvement by going for right column order in Composite Index

We had a situation where we had composite clustering key. The table had ~30 million rows. Composite clustering key (column1_lessSelective, Column2_MostSelective,Column3_Bit). The query was performing poorly, as joining the other tables with lessSelective column was slowing down the query. Changing the order of columns made the query to run pretty fast. composite clustering key (Column2_MostSelective, column1_lessSelective ,Column3_Bit). Now, Column2_MostSelective was used in JOINS and result was very high performing query. The time reduced from 9 minutes to 13 seconds.