About of Server-Client connections

Hi,

I downloaded Day20_BLE_UART project. I examined project.

I have some questions.

         -How is the pair client-server devices.

         -How does the connection happen automatically? 

         -Client Central, Server Peripheral. The client wants to connect to the server. 

         - Assume that, A Client B Server C Server.  A  UART_to_BLE_central software. B-C UART_to_BLE_peripheral software. How to set up which server  is pair to A ? I have reviewed the software but have not seen such a check.

Best Regards