ML06 Micro To Micro USB wiring
That cable:



Isn't just a simple (micro)USB to (micro)USB connection, there is more going on.

Normally a (micro)USB connector (for example on a phone) is configured as a peripheral meaning that is expects to be connected to a USB host which is usually a PC.

Some peripherals like a phone support USB On-The-Go which means that they can be changed from behaving as a peripheral into a host. This for example allows to use USB flash drive to be connected directly to the phone and be available for storage.

To indicate to the phone that it needs to go into USB OTG mode, there is an extra connection (pin) present in the micro-USB plug.



Note the yellow Sense/ID line. This pin is almost always unconnected in a standard micro-USB cable. Also there is usually no wire connected to it. So I would be surprised if you can even convert a standard micro-USB to a micro-USB-OTG connector. The connection isn't there and it is not accessible. Standard micro USB cables don't need this connection so it isn't included.

Conclusion: just buy that cable or any other USB-OTG cable. It is simply not worth it to try and make your own.