After completing the operations in Datasource view mode, open UI Design view mode.
Then, open the screen you want to work with the Select Box element.
In order to transfer data to the Select Box element, you must first add the custom action you created as Initial Action to the screen where the SelectBox element will be located.
To add an Initial Action, click the ADD ACTION button in Screen Properties.
In the menu that opens, hover over Initial Actions > Custom > Datasource. When you hover over the Datasource item, the custom actions you have created will be listed. From this list, click on SelectDeparment custom action.
Then drag and drop one Select Box element to the workspace.
Click on the Select Box element you dragged and dropped to enable data transfer.
Open the Options menu via the Properties panel on the right. In the drop-down menu under the Action heading, you should select the action that you created as a custom action and will provide the listing in the SelectBox. In the example scenario, select the Select Department action.
Under the Field to display heading, you should select the column with the data to be displayed in the Select Box element. Select departmentname in the example scenario.
Finally, in the drop-down menu under Field to Use as Key, select Id as key.
