diff --git a/src/main/java/org/gcube/portlets/user/td/unionwizardwidget/client/ColumnMappingPanel.java b/src/main/java/org/gcube/portlets/user/td/unionwizardwidget/client/ColumnMappingPanel.java
index dd74566..fbce402 100644
--- a/src/main/java/org/gcube/portlets/user/td/unionwizardwidget/client/ColumnMappingPanel.java
+++ b/src/main/java/org/gcube/portlets/user/td/unionwizardwidget/client/ColumnMappingPanel.java
@@ -15,6 +15,8 @@ import org.gcube.portlets.user.td.widgetcommonevent.client.event.SessionExpiredE
 import org.gcube.portlets.user.td.widgetcommonevent.client.type.SessionExpiredType;
 import org.gcube.portlets.user.td.widgetcommonevent.shared.TRId;
 import org.gcube.portlets.user.td.widgetcommonevent.shared.tr.column.ColumnDataType;
+import org.gcube.portlets.user.td.widgetcommonevent.shared.tr.column.ColumnTypeCode;
+import org.gcube.portlets.user.td.widgetcommonevent.shared.tr.column.RelationshipData;
 import org.gcube.portlets.user.td.wizardwidget.client.dataresource.ResourceBundle;
 import org.gcube.portlets.user.td.wizardwidget.client.util.UtilsGXT3;
 
@@ -316,37 +318,10 @@ public class ColumnMappingPanel extends ContentPanel {
 						storeComboUnionColumn.commitChanges();
 						ColumnData selectedSourceColumn = event
 								.getSelectedItem();
-						
-						for (ColumnData col : unionColumns) {
-							if (selectedSourceColumn.getDataTypeName()
-									.compareTo(ColumnDataType.Text.toString()) == 0
-									|| col.getDataTypeName().compareTo(
-											ColumnDataType.Text.toString()) == 0) {
-								storeComboUnionColumn.add(col);
-							} else {
-								if ((col.getDataTypeName().compareTo(
-										ColumnDataType.Integer.toString()) == 0 && selectedSourceColumn
-										.getDataTypeName().compareTo(
-												ColumnDataType.Numeric
-														.toString()) == 0)
-										|| (col.getDataTypeName().compareTo(
-												ColumnDataType.Numeric
-														.toString()) == 0 && selectedSourceColumn
-												.getDataTypeName().compareTo(
-														ColumnDataType.Integer
-																.toString()) == 0)) {
-									storeComboUnionColumn.add(col);
-								} else {
-									if (col.getDataTypeName().compareTo(
-											selectedSourceColumn
-													.getDataTypeName()) == 0) {
-										storeComboUnionColumn.add(col);
-									} else {
 
-									}
-								}
-							}
-						}
+						updateStoreComboUnionColumn(selectedSourceColumn,
+								storeComboUnionColumn);
+						
 						storeComboUnionColumn.commitChanges();
 						comboUnionColumn.redraw();
 						comboUnionColumn.enable();
@@ -458,40 +433,13 @@ public class ColumnMappingPanel extends ContentPanel {
 						comboUnionColumn.clear();
 						storeComboUnionColumn.clear();
 						storeComboUnionColumn.commitChanges();
-						
+
 						ColumnData selectedSourceColumn = event
 								.getSelectedItem();
-	
-						for (ColumnData col : unionColumns) {
-							if (selectedSourceColumn.getDataTypeName()
-									.compareTo(ColumnDataType.Text.toString()) == 0
-									|| col.getDataTypeName().compareTo(
-											ColumnDataType.Text.toString()) == 0) {
-								storeComboUnionColumn.add(col);
-							} else {
-								if ((col.getDataTypeName().compareTo(
-										ColumnDataType.Integer.toString()) == 0 && selectedSourceColumn
-										.getDataTypeName().compareTo(
-												ColumnDataType.Numeric
-														.toString()) == 0)
-										|| (col.getDataTypeName().compareTo(
-												ColumnDataType.Numeric
-														.toString()) == 0 && selectedSourceColumn
-												.getDataTypeName().compareTo(
-														ColumnDataType.Integer
-																.toString()) == 0)) {
-									storeComboUnionColumn.add(col);
-								} else {
-									if (col.getDataTypeName().compareTo(
-											selectedSourceColumn
-													.getDataTypeName()) == 0) {
-										storeComboUnionColumn.add(col);
-									} else {
 
-									}
-								}
-							}
-						}
+						updateStoreComboUnionColumn(selectedSourceColumn,
+								storeComboUnionColumn);
+
 						storeComboUnionColumn.commitChanges();
 						comboUnionColumn.redraw();
 						comboUnionColumn.enable();
@@ -510,6 +458,81 @@ public class ColumnMappingPanel extends ContentPanel {
 		vert.add(horiz);
 	}
 
+	protected void updateStoreComboUnionColumn(ColumnData selectedSourceColumn,
+			ListStore<ColumnData> storeComboUnionColumn) {
+		for (ColumnData col : unionColumns) {
+			if (selectedSourceColumn.getTypeCode().compareTo(
+					ColumnTypeCode.DIMENSION.toString()) == 0) {
+				if (col.getTypeCode().compareTo(
+						ColumnTypeCode.DIMENSION.toString()) == 0) {
+					RelationshipData sourceRelData = selectedSourceColumn
+							.getRelationship();
+					RelationshipData colRelData = col.getRelationship();
+					if (sourceRelData != null
+							&& colRelData != null
+							&& sourceRelData.getTargetTableId() != null
+							&& colRelData.getTargetTableId() != null
+							&& sourceRelData.getTargetTableId().compareTo(
+									colRelData.getTargetTableId()) == 0) {
+						storeComboUnionColumn.add(col);
+					}
+
+				}
+			} else {
+				if (selectedSourceColumn.getTypeCode().compareTo(
+						ColumnTypeCode.TIMEDIMENSION.toString()) == 0) {
+					if (col.getTypeCode().compareTo(
+							ColumnTypeCode.TIMEDIMENSION.toString()) == 0) {
+						RelationshipData sourceRelData = selectedSourceColumn
+								.getRelationship();
+						RelationshipData colRelData = col.getRelationship();
+
+						if (sourceRelData != null
+								&& colRelData != null
+								&& sourceRelData.getTargetTableId() != null
+								&& colRelData.getTargetTableId() != null
+								&& sourceRelData.getTargetTableId().compareTo(
+										colRelData.getTargetTableId()) == 0
+								&& selectedSourceColumn.getPeriodDataType()
+										.compareTo(col.getPeriodDataType()) == 0) {
+							storeComboUnionColumn.add(col);
+						}
+
+					}
+
+				} else {
+					if (selectedSourceColumn.getDataTypeName().compareTo(
+							ColumnDataType.Text.toString()) == 0
+							|| col.getDataTypeName().compareTo(
+									ColumnDataType.Text.toString()) == 0) {
+						storeComboUnionColumn.add(col);
+					} else {
+						if ((col.getDataTypeName().compareTo(
+								ColumnDataType.Integer.toString()) == 0 && selectedSourceColumn
+								.getDataTypeName().compareTo(
+										ColumnDataType.Numeric.toString()) == 0)
+								|| (col.getDataTypeName().compareTo(
+										ColumnDataType.Numeric.toString()) == 0 && selectedSourceColumn
+										.getDataTypeName().compareTo(
+												ColumnDataType.Integer
+														.toString()) == 0)) {
+							storeComboUnionColumn.add(col);
+						} else {
+							if (col.getDataTypeName().compareTo(
+									selectedSourceColumn.getDataTypeName()) == 0) {
+								storeComboUnionColumn.add(col);
+							} else {
+
+							}
+						}
+					}
+				}
+			}
+		}
+	}
+	
+	
+
 	/**
 	 * 
 	 * @return