On the following Dojo
you will find a working example, where a similar scenario to the one described is demonstrated (DropDownList with multiple datasource filters
You will notice that the DataSource is being filtered correctly and the values "Tea" and "Juice" are excluded from the dropdown. Please make sure that you are using the correct filter.logic property
(and/or) for configuring the DataSource filter.
In case the issue continues to persist, please provide an isolated example where the issue faced is reproduced. This way I will be able to provide you with further assistance if needed.