How to merge branch form with Parent using Excel sheet Function?

In my Project , I used the branch input four times . So , on downloading it I had one parent excel sheet , one child form excel sheet, and four branches excel sheet. Now my problem is how do I merge the parent excel sheet , one child form excel sheet and four branches excel sheet into one. I am not able to understand how to use VLOOKUP function here. How to proceed

There are a few examples here →

VLOOKUP is a Microsoft Excel feature, there are many step-by-step guides around, for example, →