Where clause on loop at any_itab assign

Dear Experts,

I want to use loop at where clause on a table type declared as ANY and a field Symbol<FS>.

At run time, in this table there is a field called 'SELECTED' which holds the value of selected rows from
ouput of ALV GRID.

I am writing this code inside an external subroutine.

form user_release_coll_so  using  p_ucomm like sy-ucomm
                                                       p_selfield type slis_selfield
                                                      it_selected_objects type any table.

data: <fs1> type any,
  <lv_sel> type any.

loop at it_selected_objects assigning <FS1>.   --> how to write where clause here?

assign component 'SELECTED' of structure <fs1> to <lv_sel>.

if <lv_sel> = 'X'.

endif.

endloop.

This is working fine but i need to loop at EVERY record in the loop.

Can some one tell me how can i use where clause in the above loop.

Thanks