Custom Search filter in Contact

I have a child section(with two fields) in a Contact Section. In that section,  I want to add customize search filter with a child entity column. So I got help from the support team like below:

• Secondly, into method getFilters() you should write the next script(example for OEMGroup):

var oemGroup = this.get("VistOEMGroup");

if (!oemGroup) {

                filters.removeByKey("VistOEMGroupGroupFilter");

} else {

filters.add("VistOEMGroupGroupFilter",Terrasoft.createColumnFilterWithParameter(

Terrasoft.ComparisonType.EQUAL,"VistOEMGroup", oemGroup.value));

}

But I don't know that getFilters() method already exists or do I need to add this to 'methods'.

Please help.