Hiding the field buttons (field button: Button that identifies a field in a PivotTable or PivotChart report. You can drag the field buttons to change the layout of the report, or click the arrows next to the buttons to change the level of detail displayed in the report.) also hides the page field drop area (drop area: An area in a PivotTable or PivotChart report where you can drop fields from the Field List dialog box to display the data in the field. The labels on each drop area indicate the types of fields you can create in the report.), if your report doesn't have any page fields (page field: A field that's assigned to a page orientation in a PivotTable or PivotChart report. You can either display a summary of all items in a page field, or display one item at a time, which filters out the data for all other items.).
If you hide field buttons but want to label elements of your chart that were previously identified by field button names, you can add axis titles or text boxes to the chart.