Hi Rohan,
One possible way to achieve the required functionality could be to save the primary key of selected row in a variable or structure instead of using the selected index since users could sort the internal table.
Just like you have used set_lead_selection_index( ), you can still use this but just get the index from the selected primary key of the row.
You could use the following logic:
get_index_selected_row(
EXPORTING
primary_key_selected_row "This would be key of the selected row
IMPORTING
index_selected).
lo_ref_node->set_lead_selection_index( index_selected ).
According the above logic your set lead selection is based on primary key of row selected by the user which would remain the same even after sorting the ALV table.
Regards,
Karan Ranawat