excel - unique values in combobox based on another combo box -

i adding unique values in combobox2 based on selection in combobox3. when implementing same code add unique values in combobox3 based on selection on combobox2, not working. replaced combobox2.value combobox3.value , column b column c.

private sub combobox1_change()  dim ws worksheet, _     dic object, _     rcell range, _     key string    set ws = worksheets("sheet1")   set dic = createobject("scripting.dictionary")   me.combobox2.clear 'clear added elements   me.combobox2.value = vbnullstring 'set active value empty string    '------here need tests-------   each rcell in ws.range("b2", ws.cells(rows.count, "b").end(xlup))     if rcell.offset(0, -1) <> me.combobox1.value     else         if not dic.exists(lcase(rcell.value))             dic.add lcase(rcell.value), nothing         end if     end if   next rcell    each key in dic     userform1.combobox2.additem key   next end sub