This actually quite a complex problem, with a very simple solution. I've encountered the same problem a couple of years ago and solved it with some basic tricks. I do not know if this is the best approach but it works.
So I will assume that you have used GUIDE to generate the matlab scripts for the GUI.
First step is to make the handle of your GUI accessible in the root memory of your PC. This is a number that matlab uses to find the GUI from a different one. use this code in the opening func of the GUI and remember the name you give to this appdata:
then later on where you want to open GUI b you use the following code to do so:
Now GUI A is linked to GUI B. In GUI B now we need to connect to GUI A. We can do this by using the initial handle of GUI_A that we saved in the root memory. In the opening function of GUI B use this code:
This code links the data saved in the structure in GUI A, so you can read and write data in that structure from GUI B.
Now if you call GUI C from GUI B you repeat this process, but you will also need to place the handle of GUI B in the root memory like you have done for GUI A to link GUI C. just add this code to the opening function of GUI B and repeat the steps of linking inside GUI C:
I hope this helps,