Dropdown list with filter option in sapui5

here two dropdown list is there .based on first list selection in the second list multiple list will visible .
a = this.getView().byId("idrfsno").getValue();
// b = this.getView().byId("idprojid").getValue();
sap.m.MessageToast.show(a);
var _this = this;

a = a.replace(/\//g, "%2F");
a = a.replace('&', "%26");

var o = "/sap/opu/odata/sap/ZPS_PROJECTCYCLE_SRV/";
this.oModelRIMBHR = new sap.ui.model.odata.ODataModel(o, true);
this.oModelRIMBHR.read("/getProjIdSet?$filter=Rfsno eq ('" + a + "')", {

success: function (oData, a) {
var jsonpro = new sap.ui.model.json.JSONModel({
idprojid: oData.results
});
_this.getView().setModel(jsonpro, "getLoaIdSet");
},