If the text cursor is on a folded line then the Select Fold command in the Fold menu selects that line and all the lines that are folded under it, without unfolding the line. If the cursor is inside a foldable range that is unfolded then that foldable range is selected. If the folded line or foldable range is inside another foldable range, only the folded line or the innermost foldable range is selected. If you repeat the command then the next larger foldable range containing the already selected range is selected.