Permuting Sparse matrices using "dissect" to Implement "Multilevel Schur complement Low-Rank" (MSLR) method to solve linear systems

I want to implement "parGeMSLR" method in matlab. [see: https://www-users.cse.umn.edu/~saad/software/ParGeMSLR/Documentation.pdf]

This need permuting sparse matrix using nested dissection. MATLAB has "dissect" function which ouput is only a permute vector. I need to have seperators and other informations.

How can I extract the requiered informations from the output of "dissect"? or is there any simple instructure to implement nested dissection? or is there any ready to use package available?

Thanks