wxPython - Combobox with Checkboxes possible?
Try with a ComboCtrl with a CheckListBox popup, or with a wx.ListCtrl plus 
CheckListCtrlMixin if you need more than one column.
Is it possible to create an Combobox with checkboxes with wxpython? 
Like most webpages have filter options in a drop down list for products where you could choose which Brand (etc.) you want.