A preliminary note about RGB fans. Each such device has TWO types of electrical connections for power and control. One is for the fan motor only and ends in a 4-pin (usually, although 3-pin also possible) female connector about 1 cm wide with holes in a line. This connector has two ridges along one side to mate with a "tongue" next to the pins of the mobo male fan header. The other is for the RGB LED system only, and may end in one of several connector types. This are is relatively new and conformance to some common "standards' is not yet complete.
What has become common are two types of RGB power and control systems. And watch for a bit of confusion: Systems like the ASUS Aura Sync are software systems that may be used with EITHER of the two electrical systems following, so you need to consider the electrical connections for compatibility issues. The simpler RGB system (often called just RGB lighting) uses type 5050 RGB strips and devices. They are fed a +12 VDC power supply on one line, and control Ground lines for the three LED colours. Thus, the connector on the end has FOUR pins or holes in a straight line, and the connector body is about 2 cm wide. In this system, the entire line of LEDS does the same thing so that the whole unit shows the same colour at any one time. If you connect several strips together using a RGB Splitter to a single source header, all the strips will do the same thing.
The other more complex system is called Addressable RGB, or ADDR RGB, or ARGB. In it each RGB node in a strip also contains a control chip to manage just the 3 LED's at that node. The entire strip (or whatever lighting device) contains a large number of such nodes, and is fed by THEE lines. One is a +5 VDC supply (NOTE not 12 VDC), one is Ground, and the third carries the control signals for all the little control chips along the strip. The controller sends out on this last line the signals for each node separately, so lighting displays can be much more complex - for example, a wave of changing colours traveling down the strip. So on one strip you can have many colours at different locations at any one time. If you connect several strips together using an RGB Splitter to a single header, all those strips likely will do the same thing. The connector for these systems looks VERY much like the one for the simpler RGB system, but it has one hole (#3) blocked off so you cannot plug it into the wrong mobo header type.
Because the supply voltage and control mechanisms for these two systems are so different, they are not compatible. So you need to match the header type provided on your mobo (3-pin ARGB or 4-pin plain RGB) with the type of RGB lighting device you buy.
To connect two or more lighting devices (of the same type) together to a single mobo RGB header you can use an RGB Splitter with two or more output arms. Typically these are designed with FOUR lines in them and 4-hole connectors, but those can be used for the 3-pin ARGB systems since that simply does not use Line #3. IF you do this, you need to ensure the overall lighting system fits the limits. Typically the RGB header (of either type) can supply up to 3 A max to lighting devices, BUT make SURE to check the specs of YOUR mobo. Then the lighting devices themselves should spec the max current each draws. For RGB fans, make sure you see SEPARATELY the current max's for the fan motor and the RGB lights.
OP, the Corsair RGB Fan LED Hub you linked is an earlier device designed by Corasir for use with many of their products, and it uses connectors to their fans that are not the same as those now becoming more common. In fact, this device does NOT suit ALL of the Corsair products - they have newer devices for newer products in their lines, so you need to check compatibility IF you are using Corsair systems. But if you are doing that - Corsair RGB fans with appropriate lighting control means - they often include with them whatever is needed to connect to and use the RGB headers on current mobos. Still, you must ensure that the lighting devices you buy (plain or ADDR RGB types) match the header type on your mobo.