DECLARE @tab table
    (
        [Char] nchar(1),
        [Pos] int
    );
 DECLARE @string nvarchar(max)

    INSERT @tab ([Char], [Pos] )
    SELECT SUBSTRING(@string, [Number], 1)
         , [Number]
      FROM [master]..[spt_values]
     WHERE ([Type] = 'p')
      AND (SUBSTRING(@string, Number, 1) IN ('{', '}'));

select * from unnest(string_to_array('foo{ - }bar abuyz dczrfz fdg{dfg67568797oryhtnP{}}{',null))with ordinality u (t,ord)
where t in('{','}')

WHILE (1 = 1)
        BEGIN
            SELECT TOP 1 @Pos1 = s1.[Pos] , @Pos2 = s2.[Pos]
              FROM @tab s1
                INNER JOIN @tab s2 ON s2.[Pos] > s1.[Pos]
             WHERE (s1.[Char] = N'{')
               AND (s2.[Char] = N'}')
            ORDER BY s2.[Pos] - s1.[Pos];

            IF @@ROWCOUNT = 0
                BREAK

            DELETE
              FROM @tab
             WHERE ([Pos] IN (@Pos1, @Pos2));

            UPDATE @tab
               SET [Pos] = [Pos] - @Pos2 + @Pos1 - 1
             WHERE ([Pos] > @Pos2);

            SET @string = STUFF(@string, @Pos1, @Pos2 - @Pos1 + 1, '');
        END

select * from unnest(string_to_array(parameter_string,null)) 
with ordinality u (sym,pos) where sym in('{','}')

--------------
SELECT	regexp_replace ('foo{ -{ }bar abuyz dczrfz fdg{dfg67568797oryhtnP{fdgfdgdfgdfg}123}dgdfgfd{' ,'\{[^\{\}]+\}' ,'<-#->' ,'ig')
	,regexp_replace ('foo{ -{ }bar abuyz dczrfz fdg{dfg67568797oryhtnP{fdgfdgdfgdfg}123}dgdfgfd{' ,'\{[^\}]+\}' ,'<-#->' ,'ig')