That looks like a "wrapped" line, not stacked chords.
The 'D Dsus2 D' part is probably just after the word 'increase' but the line was too long for one of the protocols the file has traversed, and so it got wrapped to a new line.
Some common line-length limits for text data are 72, 80, 99 (common in "beginner" software because it's so easy to type
buf and move on to "fun" stuff).
This should also be easy to spot because D Dsus2 D is one of several common folk-guitar ornaments (others are D Dsus4 D, A Asus4 A, Am Asus2 Am, C Cadd9 C, C Cmaj7 C) which involve a single finger-change. So in a sense it belongs at the end of a line just after the lyric. That's the moment when the singing stops and the guitar naturally needs to doing something interesting. A "sus4" or "sus2" ornament adds that little bit of interest. Other options are: descending bass-line, jump to chromatic mediant, play the changes totally straight to add suspense, slide up to a different phrasing of the same chord, do a little solo...