1. Not much to understand from your screenshot as it's resolution is too low.
2. As for the files. Sample.mkv it's the original file (part of a torrent so I couldn't modify it-it generates errors in torrent file) and for this file I've made the CHF file to test. Sample 1 it's created with MKV Merge using the second chapter file (the one you asked about) the .txt file, as MKV Merge doesn't accept CHF files. That file was also writen by me. Originally saved as Sample 2. Should be the same file.
Chapters were embeded by me, weren't there in the original file. In android version I don't see the option to use chapters (I use the free version, I am not sure the PRO version have support for chapters), but, IIRC I read somwhere on the forum
[Feature request] Chapter Feature (.chf) please that the developpement team consider this option.