Also, if you have a selection, =GetFieldSelections(FieldName) will produce the desired effect, but you have to have a selection made. You put this formula in the Presentation tab of the Chart properties, in the Labels for Totals formula box. You use the field name that is one level above the desired totals column. So, if you have Regions, then state in a pivot table, you put this formula in the State dimension, and it will populate the Region, when a region is selected.
It isn't a real great solution, but maybe this will inspire someone else to post a better, or correct solution, maybe something with Set Analysis?
Re: How to show the name of the dimension in subtotal field?
Have you tried playing around with Indent mode (on the Style tab)? It will do most of what you need if you set up the dimensions vertical and horizontal alignment correctly.
One caution - if you need to change the partial totals, you will need to turn off indent mode, change the partial totals and re-enable partial totals, because for some strange reason, the partial totals options are grayed out when indent mode is on.
Logic will get you from a to b. Imagination will take you everywhere. - A Einstein