Yes anyone can switch their career from BPO to Power BI developer if they possess all the required skills. One can become a Power BI developer if they are having knowledge about data warehousing projects, data preparation, and data gateways. They also should have some experience with Business Intelligence analytical tools like SQL, SSRS, SSAS, and SSIS. In order to gain better understanding of these skillsets go for training course for that I will recommend you this power bi certification course from Intellipaat. This program will provide you all the required skills and help you to become a Microsoft certified Power BI developer.
Along with that have a look at this video on how Intellipaat helped Nagababu to switch his career from BPO to Power BI developer -