How do I connect a TextBox/SearchBar to a ListPicker?

The only problem I have is how to program a TextBox to be 'connected' to a ListPicker so the User can be able to search letters, words, etc. I feel like I'm kind of on the right path, but I want a bit of help to understand this TextBox + ListPicker situation.
This is what I have. (If the image doesn't show, then it means I have another problem. [How to add images to New Topic])

how to upload photo:

or copy (Ctrl+C) the phot from your PC, then press here and paste here (Ctrl +V).