grafana/public/app/features/panel/partials/metrics_tab.html

<div class="query-editor-rows gf-form-group" ng-if="ctrl.datasourceInstance">
	<div ng-repeat="target in ctrl.panel.targets" ng-class="{'gf-form-disabled': target.hide}">
		<rebuild-on-change property="ctrl.panel.datasource || target.datasource" show-null="true">
			<plugin-component type="query-ctrl">
			</plugin-component>
		</rebuild-on-change>
	</div>

	<div class="gf-form-query">
		<div class="gf-form gf-form-query-letter-cell">
			<label class="gf-form-label">
				<span class="gf-form-query-letter-cell-carret">
					<i class="fa fa-caret-down"></i>
				</span>
				<span class="gf-form-query-letter-cell-letter">{{ctrl.nextRefId}}</span>
			</label>
			<button class="btn btn-secondary gf-form-btn" ng-click="ctrl.addQuery()" ng-hide="ctrl.datasourceInstance.meta.mixed">
				Add Query
			</button>
			<div class="dropdown" ng-if="ctrl.datasourceInstance.meta.mixed">
				<gf-form-dropdown model="ctrl.addQueryDropdown" get-options="ctrl.getOptions(false)" on-change="ctrl.addMixedQuery($option)">
				</gf-form-dropdown>
			</div>
		</div>
	</div>
</div>