There are no other materials available. The best approach would be to read the paper on the original algorithm which the nodes encapsulate:
J. Hussain and C Rea, “Computationally efficient algorithm to identify matched molecular pairs (MMPs) in large datasets”, J. Chem. Inf. Model., 2010, 50, 339-348 (DOI:10.1021/ci900450m)
There is also a simplified description of the algorithm in:
S. D. Roughley, “Five Years of the KNIME Vernalis Cheminformatics Community Contribution”. Curr. Med. Chem. 2020, 27(38), 6495-6522 (DOI: 10.2174/0929867325666180904113616 (Open Access publication - no subscription required)
and then work through the example workflows to gain an understanding of how they are working, maybe adjusting some settings as you go. If you find specific settings that you don’t understand, please do ask.