再简单不过了
a=rand(3,3,3,3)

a(:,:,1,1) =

0.9501 0.4860 0.4565
0.2311 0.8913 0.0185
0.6068 0.7621 0.8214

a(:,:,2,1) =

0.4447 0.9218 0.4057
0.6154 0.7382 0.9355
0.7919 0.1763 0.9169

a(:,:,3,1) =

0.4103 0.3529 0.1389
0.8936 0.8132 0.2028
0.0579 0.0099 0.1987

a(:,:,1,2) =

0.6038 0.0153 0.9318
0.2722 0.7468 0.4660
0.1988 0.4451 0.4186

a(:,:,2,2) =

0.8462 0.6721 0.6813
0.5252 0.8381 0.3795
0.2026 0.0196 0.8318

a(:,:,3,2) =

0.5028 0.3046 0.6822
0.7095 0.1897 0.3028
0.4289 0.1934 0.5417

a(:,:,1,3) =

0.1509 0.8600 0.4966
0.6979 0.8537 0.8998
0.3784 0.5936 0.8216

a(:,:,2,3) =

0.6449 0.3420 0.5341
0.8180 0.2897 0.7271
0.6602 0.3412 0.3093

a(:,:,3,3) =

0.8385 0.7027 0.6946
0.5681 0.5466 0.6213
0.3704 0.4449 0.7948