Thank you GeonaM_26 for your response.
Actually I am aware about all these Application Notes for FOTA examples. What I can manage to find is firmware example and documentation for the PSoC 4200 BLE device acting as a HOST in FOTA over BLE, while all these examples are referred on PSoC 4200 BLE device actin as TARGET. What I am trying to implement is a PSoC 4200 BLE device (HOST), able to download firmware over BLE in another PSoC 4200 BLE (TARGET).
And till now I can't find any example / code snippet of documentation about the HOST side of FOTA procedure
CySmart has OTA host functionality. Please refer to the CySmart source code to understand the OTA bootloading flow: https://www.cypress.com/documentation/software-and-drivers/cysmart-mobile-app
Note: There is no embedded bootloader host for OTA from Cypress.