How to force change Network site multi language subdirectory base URL?

I have enabled network site and created two sites. Then I enabled WPML plugin on both sites.

1) First one is for English and all LTR languages. This one is working fine because it's base URL is like myweb.example.com. And other languages URL becomes like myweb.example.com/fr, myweb.example.com/ru etc.

2) Second one site is created for Arabic and all RTL languages. However the problem is that it's base URL is set to myweb.example.com/ar/. So now if someone wants to access another RTL language let say URDU so the URL become myweb.example.com/ar/ur.

So the problem here is that in Arabic website it appends the language code to the base URL (myweb.example.com/ar/) but my requirements are if someone want to see it in URDU it should be like myweb.example.com/ur/ not like myweb.example.com/ar/ur. So how can I do that?