How i connect multiple file transfer in single bluetooth connection

Like we have a pos application work with android tab earlier it was come dc jack for charging and micro usb port for file transferring but now days we got only micro usb port in the tab so we need multiple file should be transfer via bluetooth ,so how we transfer the multiple instrument files ( like printer , keyboard, weighing scale) to bluetooth ?

That would take a Bluetooth file transfer app, but you're more likely to find one that will do multiple files via WiFi (browser or FTP).