How to make dependant drop down lists

Hello, I have my excel file in which I need drop down lists that would be dependant on each other. I'm doing everything on one sheet. I am attaching my workbook. What I need to do is select a category first starting in cell D8, I've marked ir Selection 1, and that the selections on cell E8 would be show only values on what category I have selected on D8. The second selection cells are merged, I don't know if that's a problem... Right now E8 and the others get their list values from another list which I have stored down bellow, but it is not dependant on anything, just shows full list.
The data for the selection 1 list is on A173:A186, and the data for the second selections is on E171:Y200. I'm marking it also.
Please help!

See if you can adapt my sample file to your needs.

You need to create a list for each category, then for each of the sub-categories and then for each of the sub-sub-categories. Then use INDIRECT to pull from the required list.

Let me know if you need further help?

Good stuff, happy to help