Data chuncks with the same lenth to flip the matrix

The attached file is my current data structure. Which is simple structure with “chunks has different lenth”.
And what I want is to make the chunck with same lenth flip the matrix. so that for example
Chuck {0} to {3} has the length of 9, And want them to become Chunck {0} to {8} with lenth of 4.

The direct flip matrix dont seems to work as I want.
Hope my description make sense… Thanks for the help!!
data tree.txt (7.6 KB)