[fix](nereids) fix can not prune dereference expression

fe/fe-core/src/main/java/org/apache/doris/nereids/rules/analysis/ExpressionAnalyzer.java

@@ -312,6 +312,8 @@ public Expression visitUnboundSlot(UnboundSlot unboundSlot, ExpressionRewriteCon
                 }
                 if (firstBound.getDataType() instanceof NestedColumnPrunable) {
                     context.cascadesContext.getStatementContext().setHasNestedColumns(true);
+                } else if (firstBound.containsType(ElementAt.class, StructElement.class)) {
+                    context.cascadesContext.getStatementContext().setHasNestedColumns(true);
                 }
                 return firstBound;
             default:
@@ -1126,7 +1128,7 @@ private Optional<Expression> bindNestedFields(UnboundSlot unboundSlot, Slot slot
             }
             throw new AnalysisException("No such field '" + fieldName + "' in '" + lastFieldName + "'");
         }
-        return Optional.of(new Alias(expression));
+        return Optional.of(new Alias(expression, unboundSlot.getName(), slot.getQualifier()));
     }
 
     public static boolean sameTableName(String boundSlot, String unboundSlot) {

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/rewrite/PruneNestedColumnTest.java

@@ -414,6 +414,15 @@ public void testCteAndUnion() throws Throwable {
         );
     }
 
+    @Test
+    public void testDereference() throws Exception {
+        assertColumn("select s.city from tbl",
+                "struct<city:text>",
+                ImmutableList.of(path("s", "city")),
+                ImmutableList.of()
+        );
+    }
+
     @Test
     public void testPushDownThroughJoin() {
         PlanChecker.from(connectContext)