Multiple Drop Down Lists

TheAntony Hi,

Can you suggest me a way to create a troubleshooting guide with dropdown lists.
The issues will be categorized and when user selects a category it will show the next level of classification and at the end of hierarchy the issue will be there along with the solution.
Here we need multiple drop down lists 
the values of seconf dropdown should be dependant on the value selected in the first dropdown
the 3rd dropdown should be dependant on the value selected in 1st dropdown and so on

Thanks TheAntony  so much

Yes,exactly like that

please,I have questions:

1- the tables you inserted have filters signs ( though columns are not filtered) - are they necessary?

2- The way you got column P is that you copied column B (B6:B32) then you applied (remove duplicates) then you inserted column O accordingly(cell by cell) - ?right

thanks!