TMSFMXGrid show sorting triangle on FixedColumn


How can I show/hide a numbered triangle of indexed sorting, but not on the first row of each column, but on the first column of each row.

I want to sort an Master/detail datasets. The master data is shown by pages in a TMSFMXGrid of 2 columns and I would like to show the ordering in the same way it is shown in the grid when it is ordered in multiple columns. Something like what is shown in the image



Unfortunately this is not supported, the indexed sorting is only available on each column for the fixed row. We'll add this on our feature request list.