What to do when we want to use both a USB hub and a power bank?

[Gayantha Vitharanage]

Is it possible with a smartphone? Are there some sort of splitters? At least, can I transfer files from one device to another device (both are connected to a smartphone via a USB hub) ?

 

[Rukbat]

A USB hub switches the phone to USB Host Mode, which means the power pins are outputs, not inputs. You can use a powered hub to power the devices plugged into it from the power bank, but you can't charge the phone and use a USB hub at the same time.