I tried this code - to get the value from Odata for dropdown selection field.

When you click first select item field then one or more selection dropdown field (eg: select item ) will appear dynamically.

Below code i tried for dynamic generate field.

onPlantchange :function(){
var plant =sap.ui.getCore().byId("plant").getSelectedKey();if(plant!=0){

 var sServiceUrl ="/sap/opu/odata/SAP/Z_M_EPM_BOM_SRV/";

  var oModel =newsap.ui.model.odata.ODataModel(sServiceUrl, true);
  var filterList =[];

  var i;

 filterList.push(newsap.ui.model.Filter("Plant",sap.ui.model.FilterOperator.EQ,plant));

 oModel.read("/MatCharFieldSet",{context:null,

 async : false,filters: filterList,

 urlParameters:{"$expand" : "MatCharValuesSet"},

 success :function(data){
var res =data.results;for(i=0;i<res.length;i++){
 var fields=newsap.ui.layout.form.SimpleForm({
 editable : true,layout:"ResponsiveGridLayout",
 labelSpanL :5,
labelSpanM :5,
 adjustLabelSpan : false,
emptySpanL :0,
emptySpanM :0,
columnsL   :4,
 columnsM   :4,
 content :[newsap.m.Label({text:res[0].DescrChar,name:res[0].FieldName}),newsap.m.Select({
 items :[newsap.ui.core.Item ({text:res[i]. MatCharValuesSet.results[i].FieldValue ,key: res[i].MatCharValuesSet.results[i].FieldValue })]})]});}fields.placeAt("fields");sap.ui.getCore().byId("fields").setVisible(true);sap.ui.getCore().byId("plantSearch").setVisible(false);}});

MatCharFieldSet Json sample file:

Dyanamic Select Item list structure:

When i selected first select item like plant(Eg Choose Plant ) then it will show dynamic select item field like well field, well type, well location.

To Show Label: DescrChar (This Value : results/[0]/Descrchar)
To show Select Item: FieldValue (This Value :  results/[0]/MatCharValuesSet /results/[0]/ FieldValue. (eg: AOWQ))


SAMPLE JSON CODE:
object
d >
results>
[0]> __metadata >
      FieldName :MPP_WELL_FIELD
       Plant :Z009
       DescrChar :Well Field
       MatCharValuesSet
                >results
              [0]> _metadata
                   FieldValue : AOWQ
              [1]> _metadata
                   FieldValue : BQIA
              [2]> _metadata
                   FieldValue : RSDA
[1]> __metadata >
      FieldName :MPP_WELL_TYPE
       Plant :Z010
       DescrChar :Well Type
       MatCharValuesSet
                >results
              [0]> _metadata
                   FieldValue : JADA
              [1]> _metadata
                   FieldValue : YERE
              [2]> _metadata
                   FieldValue : SLJD
[2]> __metadata >
       FieldName :MPP_WELL_LOCATION
       Plant :Z011
       DescrChar :Well location
       MatCharValuesSet
                >results
              [0]> _metadata
                   FieldValue : UWEE
              [1]> _metadata
                   FieldValue : JKAS
              [2]> _metadata
                   FieldValue : QEET

for project concept- pls check attached file