There's probably a simpler way to do this, but I believe the code below achieves what you are after:
% test data
x1 = randi([5 12],1,50);
% filtered data in x2
x2 = x1;
% parameters (adjust as necessary)
ws = 6; % window size
t = 10; % threshold
n = 3; % number of points above threshold (must be >n)
for i=ws:length(x1)
idx1 = i-ws+1;
idx2 = i;
idx = (idx1-1) + find(x1(idx1:idx2) > t );
if length(idx)>n
x2(idx) = nan;
end
end
[x1; x2]
