Any group associated with your datatype can be used in a drop-down filter to filter your report.
{DATATYPES.CONTROLS_START}< div >
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR.GROUP.NAME}
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR.INPUT}
< /div >
{DATATYPES.CONTROLS_END}

By default, group members in drop-downs are sorted by name. You can also choose to sort them by ID or ORDER_NUM
{DATATYPES.CONTROLS_START}< div >
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR.GROUP.NAME}
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR(SORT=ORDER_NUM).INPUT}
< /div >
{DATATYPES.CONTROLS_END}

You may also apply filters
{DATATYPES.CONTROLS_START}< div >
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR.GROUP.NAME}
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR(SORT=ORDER_NUM,FILTER=NAME|likewild|J).INPUT}
< /div >
{DATATYPES.CONTROLS_END}

You may also apply limits
{DATATYPES.CONTROLS_START}< div >
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR.GROUP.NAME}
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR(SORT=ORDER_NUM,LIMIT=6).INPUT}
< /div >
{DATATYPES.CONTROLS_END}

Or only display options for which there are results.
{DATATYPES.CONTROLS_START}< div >
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR.GROUP.NAME}
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR(SORT=ORDER_NUM,ONLY_WITH_DATA=TRUE).INPUT}
< /div >
{DATATYPES.CONTROLS_END}

(Note that you can use IGNORE_FILTERS to prevent your drop-downs from getting filtered by their own values.)
You can display the selected option in your report output
{DATATYPES.SHOW_DATATYPE.MONTH_OF_YEAR_SELECTOR}
You can also require that a filter selection be made prior to displaying results:
{|VANISHIF|DATATYPES.SHOW_DATATYPE.REGION_SELECTOR.ID}< div class='error-message'> < p >You must select a region< /p >< /div >
{/|VANISHIF|}
{|SHOWIF|DATATYPES.SHOW_DATATYPE.REGION_SELECTOR.ID}
...
{/|SHOWIF|}