That is NOT a 5 dimensional array.
While you may THINK of it as a set of points that live in 5 dimensions, it is NOT a 5-d array. You CANNOT use interpn to interpolate that data. NOT. Period. NOT.
THIS is a 5-dimensional array:
A = rand(2,3,4,5,6);
2 3 4 5 6
You can then use tools like griddatan or scatteredInterpolant to interpolate such data.
If you want to view the data as 5 independent streams of ONE dimensional data, then you can still use interp1 to interpolate. For example:
A = rand(100,5);
t = (1:100)';
0.35284 0.051081 0.32818 0.34913 0.75639
Only you know what the array represents. By themselves, numbers are just numbers. Only you know what they represent.