default void updateFilterByWithGlobalFilter(FacesContext context, Map<String, FilterMeta> filterBy) {
        // #globalFilter sets the default value, which will be assigned to the "globalFilter" input
        String globalFilterDefaultValue = getGlobalFilter();
        // if #globalFilter is set, the "globalFilter" is mandatory
        Set<SearchExpressionHint> hints = LangUtils.isBlank(globalFilterDefaultValue)
                ? SearchExpressionUtils.hintsIgnoreNoResult()
                : null;
        UIComponent globalFilterComponent = SearchExpressionUtils.contextlessResolveComponent(
                context, (UIComponent) this, GLOBAL_FILTER_COMPONENT_ID, hints);
        if (globalFilterComponent != null) {
            if (globalFilterComponent instanceof ValueHolder) {
                ((ValueHolder) globalFilterComponent).setValue(globalFilterDefaultValue);
            }
            FilterMeta globalFilterBy = FilterMeta.of(globalFilterDefaultValue, getGlobalFilterFunction(), isFilterNormalize());
            filterBy.put(globalFilterBy.getColumnKey(), globalFilterBy);
        }
    }
ID of the global filter component
primefaces/src/main/java/org/primefaces/component/api/UITable.java