How to assign selected value from auto complete extender function to another functionn

See more:

C#4.0

ASP.NET4

SQL-Server-2014

hi friends

I am using auto complete extender using jquery through webservice. I have two textboxes.for both I am using autocomplete extender.
Ex:

Material group    Material Name
MaterialGroup1    MaterialName1
                  MaterialName2
                  MaterialName3
MaterialGroup2    MaterialName4
                  MaterialName5

Here my question is when I select materialGroup1 in one textbox through autocomplete extender the corresponding materialnames(from MaterialName1 to MaterialName3) should be populated in auto completeextender in another textbox.

how to achieve this using jquery.

What I have tried:

here my jquery function is

function SearchText() {

        $(".autosuggest").autocomplete({
        
        source: function (request, response) {            
            $.ajax({
                type: "POST",
                contentType: "application/json; charset=utf-8",
                url: "MaterialRequestForm.aspx/GetAutoCompleteData",

                data: "{'MaterialName':'" + this.term + "'}",
                dataType: "json",

                success: function (data) {
                    if (data.d.length > 0) {
                        response($.map(data.d, function (item) {
                            return {
                                label: item.split('/')[0],
                                val: item.split('/')[1],
                               
                            }
                        }));
                    }
                    else {
                        response([{ label: 'No Records Found', val: -1 }]);
                    }
                },
                error: function (result) {
                    alert("Error");
                }
            });
        },
        select: function (event, ui) {
            //if (ui.item.val == -1) {
            //    return false;
            //}
            var disid  = $(this).attr("data-id");
            $(".id-group").find(".col-md-12").each(function(){
                if (disid == $(this).find("input[type=text]").attr("data-id")) {
                    $(this).find("input[type=text]").val(ui.item.val);
                }
            });
        }
    });

Here I am assigning material Id to textbox on selection of Material name.
how to populate the data based on selected value in auto complete extnder.