With your data as below in sheet 1, and Combobox1 and Listbox1 in sheet2, then:-
Right click sheet2 "Tab" , select "View Code" and Paste the Code below.
NB:- Combox1 will load when you Activate sheet2 and ListBox1 will fill when you select from Combobox1
NB:- Ensure there is a blank line at the end of each "Product Range "
Code:
Private [COLOR="Navy"]Sub[/COLOR] ComboBox1_Change()
[COLOR="Navy"]Dim[/COLOR] Rng [COLOR="Navy"]As[/COLOR] Range, Dn [COLOR="Navy"]As[/COLOR] Range
[COLOR="Navy"]With[/COLOR] Sheets("Sheet1")
[COLOR="Navy"]Set[/COLOR] Rng = .Range("B:B").SpecialCells(xlCellTypeConstants)
[COLOR="Navy"]End[/COLOR] With
[COLOR="Navy"]For[/COLOR] [COLOR="Navy"]Each[/COLOR] Dn [COLOR="Navy"]In[/COLOR] Rng.Areas
[COLOR="Navy"]If[/COLOR] Dn(1).Offset(, -1).Value = ComboBox1.Value [COLOR="Navy"]Then[/COLOR]
ListBox1.List = Dn.Value
[COLOR="Navy"]End[/COLOR] If
[COLOR="Navy"]Next[/COLOR] Dn
[COLOR="Navy"]End[/COLOR] [COLOR="Navy"]Sub[/COLOR]
Private [COLOR="Navy"]Sub[/COLOR] Worksheet_Activate()
[COLOR="Navy"]Dim[/COLOR] Rng [COLOR="Navy"]As[/COLOR] Range, r [COLOR="Navy"]As[/COLOR] Variant, Sp [COLOR="Navy"]As[/COLOR] Variant, Dn [COLOR="Navy"]As[/COLOR] Range
[COLOR="Navy"]With[/COLOR] Sheets("Sheet1")
[COLOR="Navy"]Set[/COLOR] Rng = .Range("A:A").SpecialCells(xlCellTypeConstants)
[COLOR="Navy"]End[/COLOR] With
ComboBox1.Clear
[COLOR="Navy"]For[/COLOR] [COLOR="Navy"]Each[/COLOR] Dn [COLOR="Navy"]In[/COLOR] Rng
ComboBox1.AddItem Dn.Value
[COLOR="Navy"]Next[/COLOR] Dn
[COLOR="Navy"]End[/COLOR] [COLOR="Navy"]Sub[/COLOR]
[TABLE="width: 122"]
<colgroup><col width="27" style="width: 20pt; mso-width-source: userset; mso-width-alt: 967;"> <col width="72" style="width: 54pt; mso-width-source: userset; mso-width-alt: 2560;"> <col width="64" style="width: 48pt;"> <tbody>[TR]
[TD="class: xl63, width: 27, bgcolor: #DAEEF3"] [/TD]
[TD="class: xl63, width: 72, bgcolor: #DAEEF3"]
A[/TD]
[TD="class: xl63, width: 64, bgcolor: #DAEEF3"]
B[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
1[/TD]
[TD="class: xl64, bgcolor: #DCE6F1"]
Trial 1[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 1[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
2[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 2[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
3[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 3[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
4[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 4[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
5[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 5[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
6[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
7[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Trial 2[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 6[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
8[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 7[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
9[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 8[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
10[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 9[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
11[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
12[/TD]
[TD="class: xl66, bgcolor: white"]
Trial 3[/TD]
[TD="class: xl66, bgcolor: white"]
Product 10[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
13[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 11[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
14[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 12[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
15[/TD]
[TD="class: xl65, bgcolor: #DCE6F1"] [/TD]
[TD="class: xl65, bgcolor: #DCE6F1"]
Product 13[/TD]
[/TR]
[TR]
[TD="class: xl63, bgcolor: #DAEEF3, align: right"]
16[/TD]
[TD="class: xl66, bgcolor: white"] [/TD]
[TD="class: xl66, bgcolor: white"]
Product 14[/TD]
[/TR]
</tbody>[/TABLE]