I use the regex
(\{[^{}]+\}\,[ ]{0,1}){4,4}
to search in
{ 0, 1, 2}, {1, 1, 2}, { 2,1,2}, {3,1,2},
using the mini search window.
It finds 3 matches,
{ 0, 1, 2}, {1, 1, 2}, { 2,1,2}, {3,1,2},
{1, 1, 2}, { 2,1,2}, {3,1,2},
and
{ 2,1,2},
The last two are wrong, as the pattern calls for 4 braces