ALV Tree Subtotal

Dear All,

I'm working on a ALV tree using cl_gui_alv_tree. My requirement is to calculate the percentage of column B in the header node using the subtotal value of column A.

However, when using CALL METHOD g_alv_tree->GET_OUTTAB_LINE after CALL METHOD g_alv_tree->update_calculations, the subtotal value is returning 0 value. Please let me know how to get the subtotal value in the header node.

Thank you.