Free Text Search in filtering select

Hi ,
I am using filtering select where dropdown is having large values so when i search for text it only searches for First letter of dropdown which is also in capital . so now i have 2 concerns
1- if put any text that is free text than all values that match should come . how to implement this ?
2- currently filtering select is filtering only on first capital letter of dropdown options

You will have to create a MemoryStore with a custom queryEngine and then set the store to your filtering select. Something like this

           var memData = new Memory({
                idProperty: 'Id', data: items,
                queryEngine: lang.hitch(this, this._customQueryEnginge)

            this.set('store', lang.clone(memData));