two combo boxes connecting by selecting value

[Kev_1988]

Hi

I've created a "frmResult" form, with two combo boxes.
Now I've named the first combo box: Product Name
Second combo box: Test Sample

What I want is in the first combo box: Product Name, selecting only products that's already selecting.
But the second one is tricky, for second combo box: Test Sample, I only want to select between: Test Sample A or Test Sample B or Test Sample C. (not selecting by Result 1 and Result 2 and so on)
-Test Sample A contains 2 columns
-Test Sample B contains 2 columns
-Test Sample C contains 2 columns

So in other words if I select for Product Name: DevTab2
And for Test Sample: Test Sample A
It's only shows result: 2 hits (if I'm correct)
First one:
-Test Sample A, Result 1 = blue
-Test Sample A, Result 2 = red

Second one:
-Test Sample A, Result 1 = blue
-Test Sample A, Result 2 = yellow

Hope you understand me what I'm trying to tell
What vba code can I use in order to get what I want?
I'll add my file so you can see it for yourself

Note: I'm a beginner with Access and VBA please be patient with me

Please help me out..
Thanks a lot

 

[JHB]

...
What I want is in the first combo box: Product Name, selecting only products that's already selecting.

How do you decide which product that's already selecting.

...
But the second one is tricky, for second combo box: Test Sample, I only want to select between: Test Sample A or Test Sample B or Test Sample C. (not selecting by Result 1 and Result 2 and so on)

Could you show what you mean!

 

[Kev_1988]

I've added a picture hope you will understand it better

How do you decide which product that's already selecting.

Could you show what you mean!